# SQ subs?



## ebrahim (Sep 21, 2009)

Generally speaking if we all had to look at the industry 2020 product lineup that is available in the  which companies make SQ subs that are reliable and where the dealers, distributors and possibly manufactures won’t bend you over when it comes to availability and warranting? Plus under the $500/sub. 

So far I can only think of the following:

Morel Primo
Arc Audio
Helix
Image Dynamics

Any others am I missing out in the $500 or less per sub. Pricing is on retail and not used. 

Thank you. 


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## gijoe (Mar 25, 2008)

Just about any sub can be an “SQ sub” if it’s in a proper box. Subs are far more forgiving than high frequency speakers, displacement is king. We barely hear distortion in low frequencies, and a lot of the distortion we do hear simply makes the sub sound louder.

Pick the sub that models best off of the power you intend to use, and the enclosure size/type you intend to use.


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## ebrahim (Sep 21, 2009)

Well I am not sure if I am truly doing this correctly but I am looking at how much space I want to sacrifice and then look at which subwoofer can fit in that amount of space first whether it be sealed or ported 


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## gijoe (Mar 25, 2008)

ebrahim said:


> Well I am not sure if I am truly doing this correctly but I am looking at how much space I want to sacrifice and then look at which subwoofer can fit in that amount of space first whether it be sealed or ported
> 
> 
> Sent from my iPhone using Tapatalk


That’s how I recommend you start. Determine how much space you are willing to sacrifice, figure out rough internal volume based on that, then decide what type of enclosure you want to use. With those things figured out you can use WinISD to see which sub works best with what you’re working with.


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## ebrahim (Sep 21, 2009)

True and go from there. As far as power wise I would like to stay around the 500 -900 watts rms power range 


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## gijoe (Mar 25, 2008)

ebrahim said:


> True and go from there. As far as power wise I would like to stay around the 500 -900 watts rms power range
> 
> 
> Sent from my iPhone using Tapatalk


That’ll be something you can plug into WinISD and see which sub performs better with the power you are using. That much power can be more than enough with the right sub/enclosure combo.


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## ebrahim (Sep 21, 2009)

So in the WinISD I just put the measurements and it will tell me how much cu foot and see which subwoofer enclosure can work in that enclosure


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## gijoe (Mar 25, 2008)

ebrahim said:


> So in the WinISD I just put the measurements and it will tell me how much cu foot and see which subwoofer enclosure can work in that enclosure
> 
> 
> Sent from my iPhone using Tapatalk


You put in the speaker’s TS parameters, and it calculates the “ideal” enclosure. From there you can adjust the box volume, tuning frequency, available power, etc. and see how your setup works for each sub.


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## mpm17 (Jun 2, 2019)

Don't forget Dayton Audio HO and HF series of subs. Affordable quality in my mind.


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## ebrahim (Sep 21, 2009)

mpm17 said:


> Don't forget Dayton Audio HO and HF series of subs. Affordable quality in my mind.


I heard people talk about them at Spring Break Nationals years ago. One of the gentleman in the conversation group mentioned they are made by Fi Audio but not sure how correct his statement was. 

Also if I am not mistaken one of my friends had one years ago and liked it. My concern with those subs is that the weight factor since I will be taking the enclosure out when I take my mom shopping to Costco twice a month. 


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## cman (Aug 24, 2020)

I’m also shopping for a sub $500 SQ sub right now. The Dayton HO and Ultamax are on my shortlist. they have low LE, multiple shorting rings, high xmax for a great price


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## RatesTrader (Nov 1, 2019)

Gijoe has helped me many times the last number of months. I too was looking for a sub that played tight, clean, etc. that could handle some classic rock, jazz, etc. but still able to get down and dirty if needed. I was also looking at an IDQ when my installer told me he had a pretty mint Eclipse Aluminum 88100 DVC built back in the day by TC Sounds. Being out of the scene since the 90’s I thought there was no way an almost 20 year old sub even in excellent condition would fit the bill. Wow, was I wrong! Granted, the sealed box I have it in currently is a bit too small as I lose that low end extension (it’s there but not as pronounced) but it definitely fits the SQ definition while certainly able to get rowdy while always maintaining its composure. He’s building a custom 1.125 sealed box for me now which should make the sub a bit happier. Excuse my rant but my point was there’s some subs out there that I never would’ve thought about that are excellent. I consider myself fortunate that he happened to have this gem sitting around looking for a new home.

Edit: the current sealed box is currently .67 and .58 net with sub.


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## cman (Aug 24, 2020)

RatesTrader said:


> Gijoe has helped me many times the last number of months. I too was looking for a sub that played tight, clean, etc. that could handle some classic rock, jazz, etc. but still able to get down and dirty if needed. I was also looking at an IDQ when my installer told me he had a pretty mint Eclipse Aluminum 88100 DVC built back in the day by TC Sounds. Being out of the scene since the 90’s I thought there was no way an almost 20 year old sub even in excellent condition would fit the bill. Wow, was I wrong! Granted, the sealed box I have it in currently is a bit too small as I lose that low end extension (it’s there but not as pronounced) but it definitely fits the SQ definition while certainly able to get rowdy while always maintaining its composure. He’s building a custom 1.125 sealed box for me now which should make the sub a bit happier. Excuse my rant but my point was there’s some subs out there that I never would’ve thought about that are excellent. I consider myself fortunate that he happened to have this gem sitting around looking for a new home.



That is awesome, some designs stand the test of time. My dynaudio mids are 10+ years old and are as good or better than any others i have tried.


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## RatesTrader (Nov 1, 2019)

Exactly cman. Some gear, no matter how old it may be just works. Admittedly, without my installer showing me the Eclipse and it’s details, “story” I wouldn’t have given it a second look but I’m glad he took the time. If it’s quality and does what it’s supposed to age doesn’t matter. Very happy with that single 10”. Glad to hear you have something similar!


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## ebrahim (Sep 21, 2009)

RatesTrader said:


> Gijoe has helped me many times the last number of months. I too was looking for a sub that played tight, clean, etc. that could handle some classic rock, jazz, etc. but still able to get down and dirty if needed. I was also looking at an IDQ when my installer told me he had a pretty mint Eclipse Aluminum 88100 DVC built back in the day by TC Sounds. Being out of the scene since the 90’s I thought there was no way an almost 20 year old sub even in excellent condition would fit the bill. Wow, was I wrong! Granted, the sealed box I have it in currently is a bit too small as I lose that low end extension (it’s there but not as pronounced) but it definitely fits the SQ definition while certainly able to get rowdy while always maintaining its composure. He’s building a custom 1.125 sealed box for me now which should make the sub a bit happier. Excuse my rant but my point was there’s some subs out there that I never would’ve thought about that are excellent. I consider myself fortunate that he happened to have this gem sitting around looking for a new home.
> 
> Edit: the current sealed box is currently .67 and .58 net with sub.


I sat in a vehicle with Eclipse subs mind you it was a vehicle tuned for IASCA SQ completion lanes. He had a pair of 12’s sealed and when I heard it had hardly any output but after the fact I learned those guys that compete are anal about having their midbass playing below 80 hertz so I did not get to truly hear the subwoofer playing like 80 hertz and below. If I am not mistaken the gentleman had it crossed it way low. 

Plus most installers in Orlando won’t install Eclipse subwoofers since Eclipse closed down or they using that to make me buy a subwoofer that I don’t want. 


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## rmenergy (Feb 15, 2009)

Here are 3 great subs that are often overlooked. You'll be SOL for finding local dealers but good for DIY.










ScanSpeak Discovery 26W/4558T 10" Subwoofer


ScanSpeak Discovery Line 26W/4558T 10" Subwoofer - 4 ohms. The Discovery series offer traditional design, superior sound, a solid construction, and a wide range of variants. Combining these elements - plus a wealth of technical features and finesses - gives our customers the possibility of...




www.madisoundspeakerstore.com













Seas L26RO4Y 10" Subwoofer - 4 Layer VC - (D1004-04)


Seas L26RO4Y-D0004 subwoofer used in Linkwitz Orion 3-way speaker.




www.madisoundspeakerstore.com













Home


Eminence Lab 12C High Power 12" Subwoofer Speaker Driver 4 OhmThe LAB 12C, from Eminence, is a 4-ohm take on the original LAB 12 subwoofer (for more information on the LAB 12, visit the History of the LABhorn thread at ProSoundWeb). The 12C features the same long-throw construction with a...




www.parts-express.com


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## Abraao8835 (Oct 12, 2020)

Image Dynamics


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## ANS (Sep 23, 2011)

CDT Audio Subwoofer HD-1000 CF



Does extremely well in a small sealed enclosure. It has a very detailed, articulate response. Not as much low end output but phenomenal for SQ.


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## dumdum (Feb 27, 2007)

Dayton aren’t made by fi... they use a stock 4 or 16 spoke basket and are a huge commercial entity, they are likely Chinese made I would think

My Dayton RSS390HF is an awesome piece of kit, hits the lows really well, with incredible accuracy! It’s fair to say it’s likely the best sub I’ve ever had, low inductance vs 99% of fifteens and can doubtless take well in excess of the power I am giving it (500wrms) it needs a larger than average enclosure, but it’s the good old iron law...


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## cman (Aug 24, 2020)

dumdum said:


> Dayton aren’t made by fi... they use a stock 4 or 16 spoke basket and are a huge commercial entity, they are likely Chinese made I would think
> 
> My Dayton RSS390HF is an awesome piece of kit, hits the lows really well, with incredible accuracy! It’s fair to say it’s likely the best sub I’ve ever had, low inductance vs 99% of fifteens and can doubtless take well in excess of the power I am giving it (500wrms) it needs a larger than average enclosure, but it’s the good old iron law...


Nice, I want the HF but would have to go with the HO dual 4 (in parallel) due to amp impedance. Or I could get two HF’s like I want and swap my amp for a 2 ohm stable instead of 1 ohm... lol.


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## cman (Aug 24, 2020)

Reason being is the HF has lower inductance.0.96mh vs 3.17.. although the HO in parallel Would be 3.17 divided by 2...still not as low as the HF single 4 ohm which is 0.96mh... not sure what to do..


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## dumdum (Feb 27, 2007)

I’d put 1.5kw with pleasure on my 15 and it would be fine... finding an amp that does that into a 4ohm load is nigh on impossible unless it’s a 3-4kw into 1ohm mono type class d...


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## dumdum (Feb 27, 2007)

cman said:


> Reason being is the HF has lower inductance.0.96mh vs 3.17.. although the HO in parallel Would be 3.17 divided by 2...still not as low as the HF single 4 ohm which is 0.96mh... not sure what to do..


The ho in parallel would be 0.56 i believe, and not 1.585 👍🏼


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## drphilb (Oct 23, 2014)

I have a pair of Morel UL12's that I would sell for 500 per sub, They have never been in a build, but I did buy them from a Morel Dealer, they were display subs. I paid 500 for them and selling them for what I paid. They retail for 1000. They only need 1.2 cubes, 16 lbs, 1000RMS each.


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## cman (Aug 24, 2020)

dumdum said:


> The ho in parallel would be 0.56 i believe, and not 1.585 👍🏼


Wow that would be just as good af the HF. Good enough to where I wouldn’t see it reasonable to switch my Rockford 1 ohm amp with another 2 ohm amp. I would be using two of the DVC 4+4ohm HO’s to get down to a 1 ohm final load. I believe the 3.17mh listed on the spec sheet is the inductance with the coils in series if I’m not mistaken or do you think it’s 3.17mh per coil?
If it’s 3.17 in series then in theory each coil would be 1.585mh so in parallel LE would be 0.7925mh...



https://www.parts-express.com/pedocs/specs/295-467--rss315ho-44-reference-ho-dvc-subwoofer-specifications.pdf



This is just a guess because I’ve seen other DVC subwoofers with their spec sheets listed with the coils wired in series...


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## gijoe (Mar 25, 2008)

You have a lot of good options. I loved the old Image Dynamics that I used to have, Dayton has some great subs. To put into perspective my confidence in "entry level" subs, I am currently using a single Audio Frog G10D4. The G10D4 is 2 tiers below the GB series, and I picked one up for $99. I have it in a ported box tuned low, and I have 500 watts available for it. I wouldn't need anything more than this, the response is smooth, and needed very little EQ. I get more than enough SPL from it for music, and even enthusiastic hip-hop at 80 MPH on the highway isn't a problem. 

My previous setup was a pair of Acoustic Elegance SBP 15's running IB. These subs are brilliant, and I wouldn't hesitate to buy them again, if I can run IB in the future, but the low distortion, and low inductance didn't really offer a huge advantage in my car build. Maybe if used as the low end of a pair of towers their strengths could shine, but in the car they were low passed well below what they are capable of, so that bandwidth went to waste. 

Overall my point is, you don't need to spend a lot for good bass. Find 3-4 subs that meet your price point, and can handle the power you have available. Then, model them all in the enclosure size/type that you intend to use, and compare the graphs to see which one fits your goals best.


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## RatesTrader (Nov 1, 2019)

Forgive me for the confusion. I wasn’t saying to go with an Eclipse sub as I did. I was merely trying to say that there are A LOT of very good subs out there that don’t get the recognition that they should. I brought up my Eclipse scenario because it was a sub I wasn’t even thinking about. It was by chance that my installer had one around that fit my application perfectly and I’m glad he pointed it out. I hope this helps!


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## gijoe (Mar 25, 2008)

RatesTrader said:


> Forgive me for the confusion. I wasn’t saying to go with an Eclipse sub as I did. I was merely trying to say that there are A LOT of very good subs out there that don’t get the recognition that they should. I brought up my Eclipse scenario because it was a sub I wasn’t even thinking about. It was by chance that my installer had one around that fit my application perfectly and I’m glad he pointed it out. I hope this helps!


Also consider that loudspeaker technology hasn't changed much for 100 years. Yes we have fancy new cone materials, and some tricks to reduce distortion, and increase output, but overall speakers now aren't significantly different than they were 20 years ago. This is why there is still love for "old school" gear. Unless it's broken, an old speaker is just as good as it ever was, and plenty of old speakers can be used in the same hi-fi scenarios as a modern speaker. Considering the simplicity of a subwoofer, it's no surprise that there are plenty of great options floating around for very good prices. 

As I mentioned, I would still buy another pair of SBP 15's, or some other world class subwoofers, but I will admit that most of the advantages of a speaker like that go unused in a car where the subwoofer is behind the listener, and where road noise is a much bigger issue than low frequency distortion.


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## Ge0 (Jul 23, 2007)

And here I've been satisfied with a single 10" sub and about 500W for my last two builds. I love my bass. But also like a well balanced sound as well. I'm going to throw the Sundown Audio SD4 out there as an option as well. I really dig this little sub.

Ge0


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## RatesTrader (Nov 1, 2019)

With you Ge0. I have one 10” sub, sealed box and 500 watts.


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## dumdum (Feb 27, 2007)

cman said:


> Wow that would be just as good af the HF. Good enough to where I wouldn’t see it reasonable to switch my Rockford 1 ohm amp with another 2 ohm amp. I would be using two of the DVC 4+4ohm HO’s to get down to a 1 ohm final load. I believe the 3.17mh listed on the spec sheet is the inductance with the coils in series if I’m not mistaken or do you think it’s 3.17mh per coil?
> If it’s 3.17 in series then in theory each coil would be 1.585mh so in parallel LE would be 0.7925mh...
> 
> 
> ...


That will be in series like you say as the specs are with the coils in series

The sq team I do a lot of tuning for are just doing a build with a pair of the rss315ho-44

It’s a shame they don’t do the hf in a dual coil, I’d have been on a pair of 315hf-44 like a shot 😎


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## 420tabbycat (Dec 23, 2013)

Dayton RSS265-44 ho has been serving me well for ~ $160. I’m currently searching for information on the perception of distortion. So far it seems like there are better places to spend then on a premium subwoofer. Anyone wanting to throw some numbers on where, frequency wise, perception of distortion begins to “matter” please do. I’ll even purpose that some like certain types of distortion when present.


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## gijoe (Mar 25, 2008)

420tabbycat said:


> Dayton RSS265-44 ho has been serving me well for ~ $160. I’m currently searching for information on the perception of distortion. So far it seems like there are better places to spend then on a premium subwoofer. Anyone wanting to throw some numbers on where, frequency wise, perception of distortion begins to “matter” please do. I’ll even purpose that some like certain types of distortion when present.


Check this out:
distortion


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## 420tabbycat (Dec 23, 2013)

People shun the aura 3” because distortion at the low end ~300hz. So we can all relax a little?


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## Bchester6 (Jan 15, 2020)

Subs sub. As Gijoe stated earlier, not a whole lot of technology break throughs with subwoofers so your options are plentiful. I go with the one that plays best in my current enclosure.


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## ebrahim (Sep 21, 2009)

Truth be told the shop I went to get my Oracle lights done also carried JL Audio subwoofers as well as Phoenix Gold, Sony, JBL and Kenwood. 

Truthfully they did not excite me at all. However I may truly look into Dayton, Fi Audio Alpha, Image Dynamics IDQ and the IDMAX. However a friend of mine mention that Digital Designs has their HiDef series which DD Audio considers it their SQ lineup. 

Another friend of mine suggested to me the Focal subs as well. However I hardly ever heard a Focal subwoofer playing since over here in Orlando it’s either JL Audio or some SPL subwoofer they have in their ride for example Massive Audio, Kicker, Audiopipe and others. 


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## LBaudio (Jan 9, 2009)

Me myself am the fan of JBL GTI, but had also gret results with older KEF drivers and with Focal Audiom WX27. One of best price/performance subs were TREO TSX.


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## Sam Spade (Mar 16, 2020)

I have it on good advice from someone who sells Brax/helix that the Hybrid Audio Clarus in a 12 is awesome. No idea how much in the US though. If my two new Brax Matrix ML8 subs don't do the job in a large 4WD station wagon I'll be trying the clarus.


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## Fish Chris 2 (Dec 18, 2019)

gijoe said:


> Just about any sub can be an “SQ sub” if it’s in a proper box. Subs are far more forgiving than high frequency speakers, displacement is king. We barely hear distortion in low frequencies, and a lot of the distortion we do hear simply makes the sub sound louder.
> 
> Pick the sub that models best off of the power you intend to use, and the enclosure size/type you intend to use.


So true ! I don't know how many different brands / sizes of subs Ive owned in 30 years, but probably at least 20 brands, from 8"s to 18"s... and as it turns out, my current sub (somewhat of a budget brand 18"... Skar ZVX) "in its current enclosure" is the best sounding sub, I've ever owned. I swear if you could only hear it, without seeing it, I might be able to convince you, that it was four 8"s, or 10"s. Super tight, fast, and articulate. But then on really deep stuff, it can do lightweight hair tricks. Fun


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## drphilb (Oct 23, 2014)

I just sold a 10 Morel Elate to my next door neighbor and we made a glass enclosure with a 3/4 baffle top with a cube of about .85 = 24liters powered with a Slash 300/2 bridged and it sounds pretty damn good. Sub was only 250 and never played so I bought it new and did not use it so even though the equipment is a bit old, still sounds pretty good. My thoughts are if you know how to tune, and do the basic wiring, this is a HUGE part of making it sound good and protect it from blowing the rest is about making your tuning job easy. Fancy equipment helps with this and yes there is advantages to high end equipment but if you don't tune it right then you lost the advantage of the better equipment and in some cases there are only marginal benefits. Same goes with sound dampening. If you skip this step you give up some advantages.


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## cman (Aug 24, 2020)

Fish Chris 2 said:


> So true ! I don't know how many different brands / sizes of subs Ive owned in 30 years, but probably at least 20 brands, from 8"s to 18"s... and as it turns out, my current sub (somewhat of a budget brand 18"... Skar ZVX) "in its current enclosure" is the best sounding sub, I've ever owned. I swear if you could only hear it, without seeing it, I might be able to convince you, that it was four 8"s, or 10"s. Super tight, fast, and articulate. But then on really deep stuff, it can do lightweight hair tricks. Fun


Really? I’ve been pleasantly surprised by the performance I got out of Skar Audio’s amplifiers. Their class A/B amps sound as good as my expensive class D amp. Their class D amps are great for subs (wouldn’t use their class d on mids and highs personally) but for the price I was really took back. They are kinda big not that compact but they are made by S&I mostly... same guys that make the sundown amps. I’ve been wanting to try their subs I might give one of the ZVX as a shot… my NVX (sonic) sub has done me quite well for an excellent price so I know there are great deals out there for Bass as least


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## Jroo (May 24, 2006)

cman said:


> Really? I’ve been pleasantly surprised by the performance I got out of Skar Audio’s amplifiers. Their class A/B amps sound as good as my expensive class D amp. Their class D amps are great for subs (wouldn’t use their class d on mids and highs personally) but for the price I was really took back. They are kinda big not that compact but they are made by S&I mostly... same guys that make the sundown amps. I’ve been wanting to try their subs I might give one of the ZVX as a shot… my NVX (sonic) sub has done me quite well for an excellent price so I know there are great deals out there for Bass as least


Ill be honest, I have not really looked into the Skar equipment as I was turned off by them at first. Locally, they only people that seemed to run Skar amps or subs were younger people looking to get loud cheap. The couple of times I heard anything used was a some car shows and the cars didnt sound good. Again, this was my initial impression and I never looked again. It sounds as it they may have a few decent things in their line up now.


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## cman (Aug 24, 2020)

Yes, they to cater to the SPL crowd and a lot of people just want to get as loud as possible for as cheap as possible. But if I had to build a super cheap system that still sounded good, I sware by their class A/B amps. Or their class D for sub duty. There’s nothing for the price I’ve seen that even comes close. Everything else in the price range is like maxxsonics garbage.
I’ve never tried anything besides their amps... their speakers look questionable, subs look nice but I’m sure they favor SPL over any thought or consideration of distortion...


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## Fish Chris 2 (Dec 18, 2019)

cman said:


> Really? I’ve been pleasantly surprised by the performance I got out of Skar Audio’s amplifiers. Their class A/B amps sound as good as my expensive class D amp. Their class D amps are great for subs (wouldn’t use their class d on mids and highs personally) but for the price I was really took back. They are kinda big not that compact but they are made by S&I mostly... same guys that make the sundown amps. I’ve been wanting to try their subs I might give one of the ZVX as a shot… my NVX (sonic) sub has done me quite well for an excellent price so I know there are great deals out there for Bass as least


As a matter of fact, I'm also running this Skar 4 ch for my mids / highs, and mid bass drivers and love it too...








SKv2-100.4AB | 800 Watt 4-Channel Car Amplifier


The Skar Audio SKv2-100.4AB is an extremely powerful class A/B car multi-channel amplifier. Get competition grade power with audiophile sound quality out this 4-channel amplifier, capable of powering your entire aftermarket speaker sound stage.




www.skaraudio.com





My mono amp for the sub is the Wolfram 2400.1 though. It puts out about 2630 wts for my 18" Skar sub With impedance drop and all that, it's probably closer to 1800, but that perfect for the 18" which is rated at 1600 wts RMS...


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## dumdum (Feb 27, 2007)

Fish Chris 2 said:


> So true ! I don't know how many different brands / sizes of subs Ive owned in 30 years, but probably at least 20 brands, from 8"s to 18"s... and as it turns out, my current sub (somewhat of a budget brand 18"... Skar ZVX) "in its current enclosure" is the best sounding sub, I've ever owned. I swear if you could only hear it, without seeing it, I might be able to convince you, that it was four 8"s, or 10"s. Super tight, fast, and articulate. But then on really deep stuff, it can do lightweight hair tricks. Fun


The tight sound comes from the midbass/upper sub bass regions not the subs alone, I’m guessing you run big midbass also, turn them off and then see how it sounds 😉

the skar svx sub an sq sub. Sorry but with the mms being over half a kg it just means you’ve not heard a proper sq sub to compare


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## Fish Chris 2 (Dec 18, 2019)

dumdum said:


> The tight sound comes from the midbass/upper sub bass regions not the subs alone, I’m guessing you run big midbass also, turn them off and then see how it sounds 😉
> 
> the skar svx sub an sq sub. Sorry but with the mms being over half a kg it just means you’ve not heard a proper sq sub to compare


I'm running four 8"s, and yes, of course they contribute greatly to a tight bass sound. 
But many times when tuning and testing, I've had the mid bass drivers turned off, and that 18" is just really tight. Fast and responsive.

Maybe after building dozens of systems myself and listening to hundreds of high end systems, in the last 40 years, I don't have anything to compare to.... Wait. That's kind of rediculous.


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## SNCTMPL (Nov 23, 2014)

What do you guys think of the Adire Audio subs?
They look like they should fit this category, but I have not heard them.


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## cman (Aug 24, 2020)

I want one so bad. I think i might go with a CSS xbl2 sub instead of a Brahma one due to the shorting rings...


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## cman (Aug 24, 2020)

Im stuck between the decision of getting a nice XBL2 sub or just grabbing two of these NVX subs and calling it a day... im currently running a single one of these NVX and it honestly sounds pretty dang good but i need just a bit more output to be happy... I wonder if upgrading to a SQ sub would even net any differences in a car environment...









2 Pack of NVX VSW124v2 - Pair of 12" Car Subwoofers


BOGO 25% OFF NVX VSW124v2 12" Car Audio Subwoofers Package • 2 1200 Watt 600W RMS 12" VS-Series Dual 4-ohm Car Subwoofer 12" VS-Series Subwoofer • Dual 4-ohm Voice Coil • RMS Range: 450 - 600 Watts • Non-Pressed Paper With Woven Carbon Fiber Top • High Excursion Foam Surround • Stamped Steel...




www.sonicelectronix.com


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## Bchester6 (Jan 15, 2020)

cman said:


> Im stuck between the decision of getting a nice XBL2 sub or just grabbing two of these NVX subs and calling it a day... im currently running a single one of these NVX and it honestly sounds pretty dang good but i need just a bit more output to be happy... I wonder if upgrading to a SQ sub would even net any differences in a car environment...
> 
> 
> 
> ...


SQ subs tend to blend more and be more "musical" while not being really known for output. They tend to be what most would call transparent and their presence felt in true lower frequencies...IDMAX may be your cup of tee if looking for loud and clear.


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## gijoe (Mar 25, 2008)

Bchester6 said:


> SQ subs tend to blend more and be more "musical" while not being really known for output. They tend to be what most would call transparent and their presence felt in true lower frequencies...IDMAX may be your cup of tee if looking for loud and clear.


I definitely wouldn’t say an “SQ” sub blends any better, the ability to blend well isn’t inherent in a speaker. What most people consider an SQ sub is a low distortion sub, they aren’t necessarily any quieter than any other sub, but low distortion takes away some perceived output because low frequency distortion isn’t bothersome to us.

That’s why I say there is no real quality that classifies a sub as an “SQ” sub.


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## 420tabbycat (Dec 23, 2013)

I’m just reviewing an earlier chapter. Doesn’t blending pretty much boil down to similar amplitude and good phase behavior at chosen crossover points?


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## RyuTsuiSen (Jan 26, 2018)

cman said:


> Im stuck between the decision of getting a nice XBL2 sub or just grabbing two of these NVX subs and calling it a day... im currently running a single one of these NVX and it honestly sounds pretty dang good but i need just a bit more output to be happy... I wonder if upgrading to a SQ sub would even net any differences in a car environment...
> 
> 
> 
> ...


If you end up with the CSS please post a thread, that thing is stunning. She's so pretty 

Sent from my SM-G955U using Tapatalk


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## gijoe (Mar 25, 2008)

420tabbycat said:


> I’m just reviewing an earlier chapter. Doesn’t blending pretty much boil down to similar amplitude and good phase behavior at chosen crossover points?


Yes, blending is accomplished by having a smooth frequency response through the sub/midbass crossover. Since the subs will need to be at least 10dB louder that the midbass (for it to sound even remotely fun), but it's important that the frequency response is smooth, and not abrupt. 

This transition is really important. Most of the complaints people have about poor midbass boil down to the frequency response across this crossover point. It is really important to and and how well the levels are matched, the speakers are in phase, and how well the EQ has been used.


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## Bchester6 (Jan 15, 2020)

gijoe said:


> I definitely wouldn’t say an “SQ” sub blends any better, the ability to blend well isn’t inherent in a speaker. What most people consider an SQ sub is a low distortion sub, they aren’t necessarily any quieter than any other sub, but low distortion takes away some perceived output because low frequency distortion isn’t bothersome to us.
> 
> That’s why I say there is no real quality that classifies a sub as an “SQ” sub.


I will agree with you for the most part, however, I still would consider low distortion subs as being essential for a real SQ system. If I have to eq a sub to death after I put it in it's recommended enclosure then I just choose not to use it. I guess my definition of a "SQ" sub is one the behaves properly with little or no eq.


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## Bayboy (Dec 29, 2010)

Skimmed through a bit so forgive if this has been covered. Extension and distortion aside, what happens beyond the crossover point matters as well. Somewhat related to inductance, but I've seen very few subs that were reluctant to EQ outside of the crossover point which no good sub should exhibit. The response above what is chosen is very important to blend since the mesh area is totally affected. Usually, this is the problem many experience... they don't EQ outside of the x-over point. I will EQ all the way up to 160-200hz on a sub that's crossed at 80.

Sent from my SM-G986U using Tapatalk


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## 420tabbycat (Dec 23, 2013)

Bayboy said:


> Skimmed through a bit so forgive if this has been covered. Extension and distortion aside, what happens beyond the crossover point matters as well. Somewhat related to inductance, but I've seen very few subs that were reluctant to EQ outside of the crossover point which no good sub should exhibit. The response above what is chosen is very important to blend since the mesh area is totally affected. Usually, this is the problem many experience... they don't EQ outside of the x-over point. I will EQ all the way up to 160-200hz on a sub that's crossed at 80.
> 
> Sent from my SM-G986U using Tapatalk


Interesting, endless things to consider.


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## cman (Aug 24, 2020)

Bayboy said:


> Skimmed through a bit so forgive if this has been covered. Extension and distortion aside, what happens beyond the crossover point matters as well. Somewhat related to inductance, but I've seen very few subs that were reluctant to EQ outside of the crossover point which no good sub should exhibit. The response above what is chosen is very important to blend since the mesh area is totally affected. Usually, this is the problem many experience... they don't EQ outside of the x-over point. I will EQ all the way up to 160-200hz on a sub that's crossed at 80.
> 
> Sent from my SM-G986U using Tapatalk



Wow , I did not consider this until you brought this up... I suppose just because your slope starts at 80hz (i actually like 90hz sometimes 100hz) then at the bottom of the Xover slope there could be even higher frequencies...


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## cman (Aug 24, 2020)

RyuTsuiSen said:


> If you end up with the CSS please post a thread, that thing is stunning. She's so pretty
> 
> Sent from my SM-G955U using Tapatalk


I'm trying really hard to find a subwoofer that I can utilize my current enclosure with. Its 1.5 cu ft MDF. Sealed, but I will be adding an aero port tuned to what I deem models closest to my desired response in WinIsd..... The CSS models just beautifully... its just a bit more than i want to spend, but i might end up doing it... just concerned about my single walled baffle box being able to support the monster sub just the motor is 46 lbs.. WOW!

I also have my eyes on a Sundown SA-12 which does have a single shorting ring, but much higher inductance.... I havent decided if its worth the extra coin for a low distortion sub inside a car.... Just hate paying money for something that wont even make a difference you know...

They both have decent MMS, great linear excursion....


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## JCsAudio (Jun 16, 2014)

cman said:


> Wow , I did not consider this until you brought this up... I suppose just because your slope starts at 80hz (i actually like 90hz sometimes 100hz) then at the bottom of the Xover slope there could be even higher frequencies...


What Bayboy said would apply to all the driver passbands or crossover points which is one thing that I think separates a good tune from a not as good tune.


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## RyuTsuiSen (Jan 26, 2018)

I'm very happy to have come across this thread before I start my next build 

I straight up would've stopped tuning at the start of the slope. Gotta love the little things.

Sent from my SM-G955U using Tapatalk


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## Fish Chris 2 (Dec 18, 2019)

cman said:


> Im stuck between the decision of getting a nice XBL2 sub or just grabbing two of these NVX subs and calling it a day... im currently running a single one of these NVX and it honestly sounds pretty dang good but i need just a bit more output to be happy... I wonder if upgrading to a SQ sub would even net any differences in a car environment...
> 
> 
> 
> ...


I have two NVX 10"s that I were running right before my current setup, and they sounded really nice, they just didn't give me as much really deep bass (not enough displacement) as I prefer. But they were solid subwoofers. Never had any problems with them.


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## cman (Aug 24, 2020)

Fish Chris 2 said:


> I have two NVX 10"s that I were running right before my current setup, and they sounded really nice, they just didn't give me as much really deep bass (not enough displacement) as I prefer. But they were solid subwoofers. Never had any problems with them.


Thats where I'm at with my current NVX VSW122v2. It actually sounds damn good and takes more than rated power. But I occasionally bottom it out. Not always, but when I'm on the freeway I like to really crank it and it will bottom out sometimes. My response curve also falls off pretty steep since its a sealed enclosure, so I'm missing some of the bass sprectrum without significant EQ. Im looking into options for a nice 12 that can handle about 800-1000 watts in a ported box.

The more I read about using a sub between 20hz to 80-100hz, the more it seems that low inductance, low distortion subs do not really matter much. As long as you have them in a properly tuned enclosure and stay under 100hz it seems the inductance and what not does not become nearly as critical until you go into the midbass region...

I have never owned a low distortion sub like the Dayton HO's or an XBL2 style one so I cannot say for sure though. It seems there are two camps of people here, one side says you only need a properly tuned enclosure with a "Decent quality" sub and others that say ultra low distortion subwoofers are a must and you can totally tell a difference.


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## RyuTsuiSen (Jan 26, 2018)

cman said:


> Thats where I'm at with my current NVX VSW122v2. It actually sounds damn good and takes more than rated power. But I occasionally bottom it out. Not always, but when I'm on the freeway I like to really crank it and it will bottom out sometimes. My response curve also falls off pretty steep since its a sealed enclosure, so I'm missing some of the bass sprectrum without significant EQ. Im looking into options for a nice 12 that can handle about 800-1000 watts in a ported box.
> 
> The more I read about using a sub between 20hz to 80-100hz, the more it seems that low inductance, low distortion subs do not really matter much. As long as you have them in a properly tuned enclosure and stay under 100hz it seems the inductance and what not does not become nearly as critical until you go into the midbass region...
> 
> I have never owned a low distortion sub like the Dayton HO's or an XBL2 style one so I cannot say for sure though. It seems there are two camps of people here, one side says you only need a properly tuned enclosure with a "Decent quality" sub and others that say ultra low distortion subwoofers are a must and you can totally tell a difference.


You may could look at it and model it but I was planning on a stereo integrity SQL 12 before I got a AF GS12 bnib.

It may fit that what you need, especially with it's xmax

Sent from my SM-G955U using Tapatalk


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## cman (Aug 24, 2020)

I hear the GS12 are 80% of what a gb12 is for half the cost.... Definatley a nice sub. 

I would possibly buy a SQL but they are out of stock


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## RyuTsuiSen (Jan 26, 2018)

Boooooooo 

That's how I feel looking at sonic electronics and clicking the in stock filter, 60% of their inventory disappears 

Sent from my SM-G955U using Tapatalk


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## radiospank (Jan 28, 2013)

gijoe said:


> Just about any sub can be an “SQ sub” if it’s in a proper box. Subs are far more forgiving than high frequency speakers, displacement is king. We barely hear distortion in low frequencies, and a lot of the distortion we do hear simply makes the sub sound louder.
> 
> Pick the sub that models best off of the power you intend to use, and the enclosure size/type you intend to use.


Hmm I have to disagree, I've had DD subs, FI and they both use a similar build process and materials. They both have a similar tone and performance, sure we can model a box that produces a nice flat response but I promise you the true sq subs will sound better and cleaner. Now let me explain what cleaner means to me; sounds like all speakers are one and not components, bass is defined and detailed, low end extension is a given as any sub will play low. 

In short There is no magic box nor magic EQ to make a DD sub sound like a Morel Ultimo, I've tried believe me and it was there that I realized that I've been trying to fit a square peg in a round hole. The Ultimo not only blends with the midrange better, but it sounds like its all the same speaker instead of Oh thats a tubby round subwoofer. FI, DD have a similar sound and its rounder and doesn't express the transient response of bass as good as the Ultimo does, plain and simple. Do they get low and loud, sure but that's not only what i'm after, I want detail and crisp bass that is true to the source. my .02 cents


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## radiospank (Jan 28, 2013)

ebrahim said:


> Truth be told the shop I went to get my Oracle lights done also carried JL Audio subwoofers as well as Phoenix Gold, Sony, JBL and Kenwood.
> 
> Truthfully they did not excite me at all. However I may truly look into Dayton, Fi Audio Alpha, Image Dynamics IDQ and the IDMAX. However a friend of mine mention that Digital Designs has their HiDef series which DD Audio considers it their SQ lineup.
> 
> ...


I have the DD 2000 series 10s on sale on Ebay now, I just want to point out that it is their SQ reference woofer, but that is only relative to other brands like FI Alpha, SSA GCON, etc.. I had them in a sealed box, and ported box to DD specs just to make sure i wasn't missing anything. I liked the sealed box the best, ported is just not for me, but the point i want to make is the DD is not an true SQ woofer imo, yes it models well and isn't a peaky woofer but it doesn't compare to My Ultimo or now The pair of Ultimos i run. I tell you the detail with the Morels is just next level.


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## radiospank (Jan 28, 2013)

Bayboy said:


> Skimmed through a bit so forgive if this has been covered. Extension and distortion aside, what happens beyond the crossover point matters as well. Somewhat related to inductance, but I've seen very few subs that were reluctant to EQ outside of the crossover point which no good sub should exhibit. The response above what is chosen is very important to blend since the mesh area is totally affected. Usually, this is the problem many experience... they don't EQ outside of the x-over point. I will EQ all the way up to 160-200hz on a sub that's crossed at 80.
> 
> Sent from my SM-G986U using Tapatalk


well Why eq past the cross over point and just set the crossover point higher like 100 or 120? either way you will need eq probably but for me and my car If i cross over at 80 then the midbass isn't very good so I cross up a bit higher


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## Bayboy (Dec 29, 2010)

radiospank said:


> well Why eq past the cross over point and just set the crossover point higher like 100 or 120? either way you will need eq probably but for me and my car If i cross over at 80 then the midbass isn't very good so I cross up a bit higher


Because if you look at the summed response in the crossover area you'll begin to see how it is important to have a more natural/smooth acoustic roll-off. Crossing higher or lower doesn't make a difference in whether you should do it or not unless each driver drops like a brick, or you're using a very steep filter. 

Sent from my SM-G986U using Tapatalk


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## 420tabbycat (Dec 23, 2013)

radiospank said:


> well Why eq past the cross over point and just set the crossover point higher like 100 or 120? either way you will need eq probably but for me and my car If i cross over at 80 then the midbass isn't very good so I cross up a bit higher


Are you aware of why the 100-120 crossover points work better?


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## radiospank (Jan 28, 2013)

Bayboy said:


> Because if you look at the summed response in the crossover area you'll begin to see how it is important to have a more natural/smooth acoustic roll-off. Crossing higher or lower doesn't make a difference in whether you should do it or not unless each driver drops like a brick, or you're using a very steep filter.
> 
> Sent from my SM-G986U using Tapatalk


I hear you, maybe a little more clarification on my point will help, I was assuming you were eqing quite a bit after the crossover point but if you are just adding 3-6db of boost or cut then I guess that would be acceptable for massaging any frequencies to your desire. However, I don’t know how much EQ you are doing outside the cutoff freq so I’ll just leave at that. 



420tabbycat said:


> Are you aware of why the 100-120 crossover points work better?


Yea, For me my drop in mid bass is around 80-150 on a sub, if I set it at 80 it’s severely lacking, if I set the cross over higher like 120 it’s more Manageable with EQ to get a smoother response, either outside the cutoff or inside, point is I don’t want to attenuate the signal with a low cutoff like 80hz. Also I would like to add that I typically don’t just look at the graph response on my DSP, I will do test tones and measure the Db difference between them, so 50 hz is usually the strongest and 80hz weaker, attenuation is applied to 50hz and 80 or 100 hz boosted until the loudness to my ears is equal. I do this for all tones 30, 40, 50 ...etc. Now the sub will not be able to play generally that loud higher up so it’s a compromise for me to keep the boost low to have decent output.


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## 420tabbycat (Dec 23, 2013)

radiospank said:


> I hear you, maybe a little more clarification on my point will help, I was assuming you were eqing quite a bit after the crossover point but if you are just adding 3-6db of boost or cut then I guess that would be acceptable for massaging any frequencies to your desire. However, I don’t know how much EQ you are doing outside the cutoff freq so I’ll just leave at that.
> 
> 
> Yea, For me my drop in mid bass is around 80-150 on a sub, if I set it at 80 it’s severely lacking, if I set the cross over higher like 120 it’s more Manageable with EQ to get a smoother response, either outside the cutoff or inside, point is I don’t want to attenuate the signal with a low cutoff like 80hz. Also I would like to add that I typically don’t just look at the graph response on my DSP, I will do test tones and measure the Db difference between them, so 50 hz is usually the strongest and 80hz weaker, attenuation is applied to 50hz and 80 or 100 hz boosted until the loudness to my ears is equal. I do this for all tones 30, 40, 50 ...etc. Now the sub will not be able to play generally that loud higher up so it’s a compromise for me to keep the boost low to have decent output.


Are you not tuning with rta? And to a listening curve?


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## radiospank (Jan 28, 2013)

Yea I have an rta, and use rew but gotta trust your ears too, rew eq suggestions aren’t close but I still prefer certain things depending on the sound. Plus FYI everyone has a unique loudness curve so mine is different than yours and def different than the microphone used in calibration.


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## Bayboy (Dec 29, 2010)

I use my ears like anyone else should, but the RTA is very useful in pinpointing issues that your ears can not. So while ear method is a good tool, it's better in unison with the RTA. If you look at graphs you will be able to see what I'm referring to as far as the summed response which affects transitions where each driver hands off to the next. Doesn't matter which curve you choose to use, it still exists. In fact, unless you're very good at tuning by ear (most aren't), you probably won't be able to pinpoint which driver is the offender in summing. 

Sent from my SM-G986U using Tapatalk


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## gijoe (Mar 25, 2008)

radiospank said:


> Hmm I have to disagree, I've had DD subs, FI and they both use a similar build process and materials. They both have a similar tone and performance, sure we can model a box that produces a nice flat response but I promise you the true sq subs will sound better and cleaner. Now let me explain what cleaner means to me; sounds like all speakers are one and not components, bass is defined and detailed, low end extension is a given as any sub will play low.
> 
> In short There is no magic box nor magic EQ to make a DD sub sound like a Morel Ultimo, I've tried believe me and it was there that I realized that I've been trying to fit a square peg in a round hole. The Ultimo not only blends with the midrange better, but it sounds like its all the same speaker instead of Oh thats a tubby round subwoofer. FI, DD have a similar sound and its rounder and doesn't express the transient response of bass as good as the Ultimo does, plain and simple. Do they get low and loud, sure but that's not only what i'm after, I want detail and crisp bass that is true to the source. my .02 cents


I'm going to disagree again (no big deal). Subwoofers do not have an inherent ability to blend. The Morel doesn't blend better than the DD. The frequency response of each sub through the crossover point is what will determine how well, or poorly a speaker will blend. This frequency response can be altered by using a different enclosure, different crossovers, and by using EQ. It is not a characteristic that is built into a speaker. 

You say that "true sq subs will sound better and cleaner". What do you mean by this? What makes a sub sound better? What makes a sub sound cleaner? Typically, we can define "cleaner" as lower distortion, and while it's true that not all subs are created equal, some having much less distortion than others, the fact remains that we are VERY bad at hearing distortion in low frequencies, and many people find that low distortion subs sound too quiet due to the fact that low frequency distortion adds to the perceived output, without sounding bad. At 40hz the distortion has to be as loud as the music, which means we tolerate up to 100% distortion at 40hz. A difference between 5-10% distortion between subs will not make a big difference, and the higher distortion may even sound better. So, a case can certainly be made that higher distortion subs sound better. "Better" and "cleaner" are tricky words to get away with using in this case. 

Again, the enclosure is absolutely important, the subwoofer and enclosure work as 1 single unit. If you can't put the sub in the correct enclosure, you can't optimize its performance. Good bass is really easy if you design the box around the subwoofer you are using, have a bit of flexibility with your crossovers, and have a few bands of EQ to work with. 

A proper box, and some DSP tools goes a long way in leveling the playing field. I'm not making a blanket statement that all subs sound the same, that's ridiculous, but I am saying that it doesn't take nearly as much as some people think to get "SQ" performance from their subs. Plenty of very basic subwoofers can hold their own against the boutique brands, as long as the enclosure, and frequency response are optimized.


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## Bchester6 (Jan 15, 2020)

I would have to agree that subs tend to me more "flexible" when it comes to system integration due to their simplistic nature and true function. I certainly will always prefer a sub and enclosure combination that yield a flatter and smoother response which seem to be inherent in "SQ" subs. IMO the best subs are the ones I have to do the least to tame. For instance if I put a Boston 12.5LF in a 1 cu ft sealed box (no eq necessary) I can literally walk away and be done.


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## radiospank (Jan 28, 2013)

gijoe said:


> I'm going to disagree again (no big deal). Subwoofers do not have an inherent ability to blend. The Morel doesn't blend better than the DD. The frequency response of each sub through the crossover point is what will determine how well, or poorly a speaker will blend. This frequency response can be altered by using a different enclosure, different crossovers, and by using EQ. It is not a characteristic that is built into a speaker.


Well I have to disagree and agree on this, haha but again one has to define what "blend" means to them!
Sure can DD "blend" with the front stage, absolutely but it has inherent tonal characteristics that cannot be manipulated via enclosure and DSP (EQ). This is where I say that Morel does "blend" better as it recreates the bass signal much more pleasing than the DD. It does this by displaying detailed transients in music, and provides more resolution to the bass, where DD seems to blur the transients creating a softer or rounder sound if you will. This is hard to explain to the common man as they have no knowledge of music production and recording, but I hope I explained it at a high enough level for everyone to understand here.



gijoe said:


> You say that "true sq subs will sound better and cleaner". What do you mean by this? What makes a sub sound better? What makes a sub sound cleaner? Typically, we can define "cleaner" as lower distortion, and while it's true that not all subs are created equal, some having much less distortion than others, the fact remains that we are VERY bad at hearing distortion in low frequencies, and many people find that low distortion subs sound too quiet due to the fact that low frequency distortion adds to the perceived output, without sounding bad. At 40hz the distortion has to be as loud as the music, which means we tolerate up to 100% distortion at 40hz. A difference between 5-10% distortion between subs will not make a big difference, and the higher distortion may even sound better. So, a case can certainly be made that higher distortion subs sound better. "Better" and "cleaner" are tricky words to get away with using in this case.


Well can't argue with you here, but distortion is ambiguously perceived and you are right using general terms like better and cleaner are tricky, that is unless you define what they are; to which I did in my original post.



gijoe said:


> Again, the enclosure is absolutely important, the subwoofer and enclosure work as 1 single unit. If you can't put the sub in the correct enclosure, you can't optimize its performance. Good bass is really easy if you design the box around the subwoofer you are using, have a bit of flexibility with your crossovers, and have a few bands of EQ to work with.


 Who said it wasn't? I guess I have to reiterate that to ME a good SQ woofer must have a few constants, such as properly designed enclosure, good crossover points, good electrical, good amplifier with sufficient power, etc.. My original argument was never taking these other constants into consideration because they should be in place. I was only focusing on the sub and how it reproduces music.



gijoe said:


> A proper box, and some DSP tools goes a long way in leveling the playing field. I'm not making a blanket statement that all subs sound the same, that's ridiculous, but I am saying that it doesn't take nearly as much as some people think to get "SQ" performance from their subs. Plenty of very basic subwoofers can hold their own against the boutique brands, as long as the enclosure, and frequency response are optimized.


 SQ is relative yes, so for most of the population that cannot appreciate boutique performance, a DD 2000 series sub or any equivalent designed sub, can certainly hold its own against a Morel. I should know I have had them both and with an objective measurement I can say that the DD is not SQ to ME. 

There are many levels of performance and whatever is best for your wallet is the right choice IMO


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## radiospank (Jan 28, 2013)

Bayboy said:


> I use my ears like anyone else should, but the RTA is very useful in pinpointing issues that your ears can not. So while ear method is a good tool, it's better in unison with the RTA. If you look at graphs you will be able to see what I'm referring to as far as the summed response which affects transitions where each driver hands off to the next. Doesn't matter which curve you choose to use, it still exists. In fact, unless you're very good at tuning by ear (most aren't), you probably won't be able to pinpoint which driver is the offender in summing.
> 
> Sent from my SM-G986U using Tapatalk


yea let the rta do the heavy lifting and let your ears be the final judge, thats what I do..


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## cman (Aug 24, 2020)

Thats funny you mention FI subs. Im on the fence about ordering an SSA Icon or custom Fi sub. I want a nice SQL sub thats built in the US. But TBH JL Audio is just too expensive for what you get. I see Fi offers custom options such as shorting rings or sleeves so that would really be a plus for me even if i wont hear the difference I know its reducing inductive distortion which might mentally make me think it sounds better... LOL


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## Bayboy (Dec 29, 2010)

Avoiding terms that are too subjective or vague, subs can be categorized by accuracy. While that's still a grey area, I think most have heard the difference between a quite accurate sub vs one that is rather muddy. However, I do believe the area involved is much higher up than what many concentrate on. Inductance can play a role, but not as much as mass (mms). It takes a very careful balance of mms along with other engineered parameters to produce a sub that can dig deep with authority, but is light enough to produce the delicate upper band material accurately. However, you can not look at any parameter alone... it's the entire package, and that must be experienced, if not tested (Klippel). 

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## radiospank (Jan 28, 2013)

Looks like Icon does incorporate a shorting ring, this will help the upper response be just a tad higher instead of dropping slightly. How much I don’t know but between FI and SSA I just don’t see any difference as both use similar designs in materials and specs. As others have pointed out it’s more about the install, enclosure,electrical, crossovers, etc. I think FI Q or Ssa Icon would both do good on SQL


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## cman (Aug 24, 2020)

Nevermind, I was wrong about that.... Heard that somewhere...

FI used to build SSA's woofers, guess they are separate products now..


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## Sam Spade (Mar 16, 2020)

So if you are after SQ subs then big amps to get enough SPL and subs in a sealed box will give you a much flatter frequency response won't it?


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## Bayboy (Dec 29, 2010)

It's too subjective to say which route to go, but my preference for sealed has been low Qts subs (.3-.4) in a mid Qtc enclosures (.6) that have somewhat a high roll-off of 50-60hz or so. They're not as beefy in the 40-50 range, but tend to play more linear down into the lowest notes. Higher Q's have more presence in the meaty range but seem to fall off a bit down really low. That's all before EQ and just relying on vehicle acoustics.

Of course, there's IB & ported that can work amazingly well, so again, too subjective to say what's best. I also tend to stay away from L/R -24db electrical slopes on subs and incorporate Butterworth -12db instead as I find it more useful in extracting upper bass capabilities that help with midbass presence. YMMV. 

Basically, it boils down to driver capability and how much it takes to manipulate the response. Some are easier to work with than others. 



Sent from my SM-G986U using Tapatalk


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## cman (Aug 24, 2020)

Bayboy said:


> It's too subjective to say which route to go, but my preference for sealed has been low Qts subs (.3-.4) in a mid Qtc enclosures (.6) that have somewhat a high roll-off of 50-60hz or so. They're not as beefy in the 40-50 range, but tend to play more linear down into the lowest notes. Higher Q's have more presence in the meaty range but seem to fall off a bit down really low. That's all before EQ and just relying on vehicle acoustics.
> 
> Of course, there's IB & ported that can work amazingly well, so again, too subjective to say what's best. I also tend to stay away from L/R -24db electrical slopes on subs and incorporate Butterworth -12db instead as I find it more useful in extracting upper bass capabilities that help with midbass presence. YMMV.
> 
> ...


Interesting, I have noticed that with 24/dB slopes I’m missing a lot of mid bass or upper sub bass. I will have to experiment with different slopes as you mentioned...


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## Bayboy (Dec 29, 2010)

cman said:


> Interesting, I have noticed that with 24/dB slopes I’m missing a lot of mid bass or upper sub bass. I will have to experiment with different slopes as you mentioned...


It's one thing to try to achieve a -24db acoustic slope, but that doesn't always mean use an electrical -24db slope including type to do so. 

Sent from my SM-G986U using Tapatalk


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## Bchester6 (Jan 15, 2020)

Bayboy said:


> It's one thing to try to achieve a -24db acoustic slope, but that doesn't always mean use electrical -24db slope including type to do so.
> 
> Sent from my SM-G986U using Tapatalk


I try not to use -24db slopes as they sound thin and unnatural to me. This seems esp true when using sealed drivers that already have inherent roll off characteristics. The only thing I can tolerate them on is bass heavy music but that's not my bag.


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## Holmz (Jul 12, 2017)

Sam Spade said:


> So if you are after SQ subs then big amps to get enough SPL and subs in a sealed box will give you a much flatter frequency response won't it?


This is a blanket statement...

Ported have lower distortion and make more SPL, so they do not require as much power.
Ported and bandpass have higher group delay, but that could be addressed with a DSP.
So saying "use sealed with a lot of power", is also because sealed require more power to hit the same SPL... a flat response can also be arrived at with a DSP, and the cabin gain sort makes a flat response a combination of factors that are independent of the sub/box... assuming a car is involved.

One thing that cannot be addressed is transcient response, so that would be an arguement for sealed, and IB is even better.

One probably needs to factor in musical style and the nature of the content to arrive at a good choice.

There are a least 5 factors to weight up here:

sub
box
available power
cabin effects
Musical content
transcient response goals
SPL goals
group delay goals (DSP)
amplitude response goals (DSP)

It is not readily obvious what choices of sub and box are optimum.


----------



## ckirocz28 (Nov 29, 2017)

ebrahim said:


> Generally speaking if we all had to look at the industry 2020 product lineup that is available in the  which companies make SQ subs that are reliable and where the dealers, distributors and possibly manufactures won’t bend you over when it comes to availability and warranting? Plus under the $500/sub.
> 
> So far I can only think of the following:
> 
> ...


CSS Audio SDX10's and SDX12's
Adire Audio Brahma's, Tumult's?


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## ckirocz28 (Nov 29, 2017)

cman said:


> I want one so bad. I think i might go with a CSS xbl2 sub instead of a Brahma one due to the shorting rings...


I've got 2 of the SDX12's and they are freaking awesome, kinda heavy though. I don't think you could go wrong with a Brahma either, they hadn't reopened yet when CSS started preorders or I would have gone with Adire subs. Brahma's are lengendary subs, made in the USA, CSS is made in China and cheaper by a little bit. Your choice, they are both awesome subs.


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## ckirocz28 (Nov 29, 2017)

cman said:


> I'm trying really hard to find a subwoofer that I can utilize my current enclosure with. Its 1.5 cu ft MDF. Sealed, but I will be adding an aero port tuned to what I deem models closest to my desired response in WinIsd..... The CSS models just beautifully... its just a bit more than i want to spend, but i might end up doing it... just concerned about my single walled baffle box being able to support the monster sub just the motor is 46 lbs.. WOW!
> 
> I also have my eyes on a Sundown SA-12 which does have a single shorting ring, but much higher inductance.... I havent decided if its worth the extra coin for a low distortion sub inside a car.... Just hate paying money for something that wont even make a difference you know...
> 
> They both have decent MMS, great linear excursion....


CSS all the way if the other choice is Sundown. I don't know about that box though, ported would require a very long port. I run mine sealed in 1.25 cubic feet each with 1800 watts each, they probably see 1200 watts on music.


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## ckirocz28 (Nov 29, 2017)

cman said:


> Thats where I'm at with my current NVX VSW122v2. It actually sounds damn good and takes more than rated power. But I occasionally bottom it out. Not always, but when I'm on the freeway I like to really crank it and it will bottom out sometimes. My response curve also falls off pretty steep since its a sealed enclosure, so I'm missing some of the bass sprectrum without significant EQ. Im looking into options for a nice 12 that can handle about 800-1000 watts in a ported box.
> 
> The more I read about using a sub between 20hz to 80-100hz, the more it seems that low inductance, low distortion subs do not really matter much. As long as you have them in a properly tuned enclosure and stay under 100hz it seems the inductance and what not does not become nearly as critical until you go into the midbass region...
> 
> I have never owned a low distortion sub like the Dayton HO's or an XBL2 style one so I cannot say for sure though. It seems there are two camps of people here, one side says you only need a properly tuned enclosure with a "Decent quality" sub and others that say ultra low distortion subwoofers are a must and you can totally tell a difference.


You absolutely can tell a difference with the ultra low distortion subs, even at 150-ish db they don't "sound" loud, they sound correct/accurate/clean.


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## ckirocz28 (Nov 29, 2017)

I forgot all about Stereo Integrity's SQL series, they are supposedly very clean and very spl capable.


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## cman (Aug 24, 2020)

ckirocz28 said:


> You absolutely can tell a difference with the ultra low distortion subs, even at 150-ish db they don't "sound" loud, they sound correct/accurate/clean.



Ive been trying to model enclosures for like a week now to make a 25hz enclosure... I cant get it tuned low enough without constructing some kind of labyrinth with a slot port or with tube ports its either not enough port area or a massive tube sticking out the side of my box.... I'm going to try a box tuned to 30hz and see how it goes... if that fails I will go back to sealed. 

Im going to try a Dayton Ultimax 12 that will be here on Monday..... if that cant handle enough power to keep up with the rest of my system I'm going to get a Brahma. I hear the shorting rings are not as necessary since its such a low distortion sub by design....


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## cman (Aug 24, 2020)

ckirocz28 said:


> I forgot all about Stereo Integrity's SQL series, they are supposedly very clean and very spl capable.


I wanted to try one of those I believe they are sold out at the moment..


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## ckirocz28 (Nov 29, 2017)

Sam Spade said:


> So if you are after SQ subs then big amps to get enough SPL and subs in a sealed box will give you a much flatter frequency response won't it?


In-car, un-eq'd response will be flatter with a sealed subwoofer, the low end rolloff is countered by cabin gain, almost perfectly. Ported gives a flatter response to a lower frequency without cabin gain, such as in a home theater setup.


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## ckirocz28 (Nov 29, 2017)

cman said:


> Ive been trying to model enclosures for like a week now to make a 25hz enclosure... I cant get it tuned low enough without constructing some kind of labyrinth with a slot port or with tube ports its either not enough port area or a massive tube sticking out the side of my box.... I'm going to try a box tuned to 30hz and see how it goes... if that fails I will go back to sealed.
> 
> Im going to try a Dayton Ultimax 12 that will be here on Monday..... if that cant handle enough power to keep up with the rest of my system I'm going to get a Brahma. I hear the shorting rings are not as necessary since its such a low distortion sub by design....


You'll need about 9 feet of 6 inch pvc to make a port for an SDX12 or Brahma 12", just kidding. 
The XBL^2 design has a quite convenient place for a shorting ring between the 2 magnetic gaps, but a shorting ring is just icing on an already iced cake.


----------



## ckirocz28 (Nov 29, 2017)

cman said:


> Ive been trying to model enclosures for like a week now to make a 25hz enclosure... I cant get it tuned low enough without constructing some kind of labyrinth with a slot port or with tube ports its either not enough port area or a massive tube sticking out the side of my box.... I'm going to try a box tuned to 30hz and see how it goes... if that fails I will go back to sealed.
> 
> Im going to try a Dayton Ultimax 12 that will be here on Monday..... if that cant handle enough power to keep up with the rest of my system I'm going to get a Brahma. I hear the shorting rings are not as necessary since its such a low distortion sub by design....


For the CSS SDX12. 4" port, 31" long, 1.6 cubic feet, tuned at 25 hz.








CSS SDX12 Recommended Box Alignments


Sealed, Ported, and Passive Radiator box suggestions and response.




www.css-audio.com


----------



## cman (Aug 24, 2020)

ckirocz28 said:


> For the CSS SDX12. 4" port, 31" long, 1.6 cubic feet, tuned at 25 hz.
> 
> 
> 
> ...


The thing that concerns me about that is it says "port chuffing starts at 17m/s and is fairly audible by. ... cant remember what it says but with that size port it can get up to twice the fairly audible level.... it will be in my trunk... not sure if i would be able to hear it or not.... Ive been told that you need way more port area to not hear the chuffing... but i have only ever used slotted ports so i really dont know for sure..

the reason I wanted to try a ported design is due to the gain in efficiency... but honestly I think I'm just going to run two 12's sealed and get a 3db gain from the extra cone area + i will be pushing more power and that plus cabin gain and EQ I think I can get to where I want to be without the massive enclosure....


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## cman (Aug 24, 2020)

ckirocz28 said:


> You'll need about 9 feet of 6 inch pvc to make a port for an SDX12 or Brahma 12", just kidding.
> The XBL^2 design has a quite convenient place for a shorting ring between the 2 magnetic gaps, but a shorting ring is just icing on an already iced cake.


LOL


----------



## ckirocz28 (Nov 29, 2017)

cman said:


> The thing that concerns me about that is it says "port chuffing starts at 17m/s and is fairly audible by. ... cant remember what it says but with that size port it can get up to twice the fairly audible level.... it will be in my trunk... not sure if i would be able to hear it or not.... Ive been told that you need way more port area to not hear the chuffing... but i have only ever used slotted ports so i really dont know for sure..
> 
> the reason I wanted to try a ported design is due to the gain in efficiency... but honestly I think I'm just going to run two 12's sealed and get a 3db gain from the extra cone area + i will be pushing more power and that plus cabin gain and EQ I think I can get to where I want to be without the massive enclosure....


I ran an RE Audio HC15 in a 4 cubic foot box with a 4"x4" port 12 inches long in a hatchback, I don't remember what the port velocity was supposed to be but there was significant chuffing that could only be heard below the tuning frequency (26 hz) or with the hatch open. 150 db of bass will drown out some port noise easily.


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## ckirocz28 (Nov 29, 2017)

cman said:


> The thing that concerns me about that is it says "port chuffing starts at 17m/s and is fairly audible by. ... cant remember what it says but with that size port it can get up to twice the fairly audible level.... it will be in my trunk... not sure if i would be able to hear it or not.... Ive been told that you need way more port area to not hear the chuffing... but i have only ever used slotted ports so i really dont know for sure..
> 
> the reason I wanted to try a ported design is due to the gain in efficiency... but honestly I think I'm just going to run two 12's sealed and get a 3db gain from the extra cone area + i will be pushing more power and that plus cabin gain and EQ I think I can get to where I want to be without the massive enclosure....


That joke about 9 feet of 6" inch pvc pipe was not so much a joke as it was inaccurate, 2 6" inch pvc ports 9 feet long for 1 SDX12 tuned to 25 hz with manageable port velocity is more accurate. For those subs, passive radiators are a much more realistic solution, but more expensive too.


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## Holmz (Jul 12, 2017)

ckirocz28 said:


> That joke about 9 feet of 6" inch pvc pipe was not so much a joke as it was inaccurate, 2 6" inch pvc ports 9 feet long for 1 SDX12 tuned to 25 hz with manageable port velocity is more accurate. For those subs, passive radiators are a much more realistic solution, but more expensive too.


Arguably not really...
The time cost of putting in PVC, the PVC cost, and aeroport cost also adds up.
Then there's any drama which would require a redo, which means either hacking into the box, or cutting pipe... so it is somewhat safer Tom use a PR for the amateur.

With a PR, if it is mal tuned then one just takes it off and adjusts weights, and put it back on.

The main time one cannot use an Aeroport is for a blowthrough box...

(And secondly when the tuning freq is too high to be facilitated with a heavy PR, and thirdly when the PR would need to be on a horizontal surface with a low freq and a lot of weight.)


----------



## cman (Aug 24, 2020)

Interesting.... Ive never done much research on Passive radiators... did not realize their efficiency was the same as ported just without the port noise until reading that CSS blog post right now.... Seems CSS recommends 2 cu ft for a 25hz passive radiator setup... Seems like it would be hard to fit one of those SDX12's plus two PR's onto a 2 cu ft box....


----------



## ckirocz28 (Nov 29, 2017)

cman said:


> Interesting.... Ive never done much research on Passive radiators... did not realize their efficiency was the same as ported just without the port noise until reading that CSS blog post right now.... Seems CSS recommends 2 cu ft for a 25hz passive radiator setup... Seems like it would be hard to fit one of those SDX12's plus two PR's onto a 2 cu ft box....


You gotta keep in mind that CSS Audio is a home theater oriented company, a 2 cubic foot cube with PR's on the sides and a sub on the front is quite small and easy in a house.


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## Sam Spade (Mar 16, 2020)

Holmz said:


> This is a blanket statement...
> 
> Ported have lower distortion and make more SPL, so they do not require as much power.
> Ported and bandpass have higher group delay, but that could be addressed with a DSP.
> ...


That is really helpful Holmz Thanks

Is it also true that:

sealed boxes have no air circulation and that can affect the longevity of the drivers?
Ported boxes don't have a compressed air mass like sealed so it is easier to kill drivers from playing too loud and with excessive driver excursion?
I didn't know that sealed boxes have more distortion. Is it typically enough to hear so you can locate the sub and it stops seeming like the bass is coming from the front stage? And is it a bigger issue than noise caused by air movement through the port?

In my build I was heading towards sealed compared to single port as I don't want my system to sound like the drummer has three pillows stuffed in his bass drum, unless of course he does.

Other than sealed I'm also contemplating two chamber bandpass but that has space issues under my false floor. Which I can work around if it gives me enough SQ benefit to outweigh the space costs


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## Holmz (Jul 12, 2017)

Sam Spade said:


> That is really helpful Holmz Thanks
> 
> Is it also true that:
> 
> ...


Longer longeveirty from no dust?
Or shorter from no cooling and more power?
.



Sam Spade said:


> ...
> I didn't know that sealed boxes have more distortion. Is it typically enough to hear so you can locate the sub and it stops seeming like the bass is coming from the front stage? And is it a bigger issue than noise caused by air movement through the port?
> ...


Hanatsu posted a good article on it a few years back.

Non linear motors and motion cause distortion.
Sealed is trying to compress air in a box, so they are non linear.

Around the port freq the motor is hardly moving.

Whether distortion is good or bad can be debated... but distortion does not seem like a benefit. One could cross over higher if the harmonic distortion was lower.




Sam Spade said:


> ... And is it a bigger issue than noise caused by air movement through the port?
> ...


Rassive radiators do not have a lot of port noise....




Sam Spade said:


> ...
> In my build I was heading towards sealed compared to single port as I don't want my system to sound like the drummer has three pillows stuffed in his bass drum, unless of course he does.
> 
> Other than sealed I'm also contemplating two chamber bandpass but that has space issues under my false floor. Which I can work around if it gives me enough SQ benefit to outweigh the space costs


That is BS...
Does your current system using the PRs sound like three pillows? 

A bandpass would be much harder than a port or PR... but I would encourage you not to believe anything I say, or anyone else.

Just make three boxes... seal, Ported, and Bandpass and try them in the carport... then you would know for sure. Other wise you are making decision based on legend or some other incomplete dose of reality. I mean model all three first... and then just try it.

As you have some Chardonnay brand of DSP, then group delay should be easy to address.


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## Sam Spade (Mar 16, 2020)

Multiple articles I've read claim that lack of ventilation of the box increases the risk of thermal induced failure of a sub. But it sounds like a dodgy claim to me. Never seen data on it. 

Re the three pillows analogy i was overstating for effect. But the subs ive heard in enlosed boxes have seemed tighter and less boomy than ported. Which aligns with this quote:

_John Marks further adds;

“The advantages of a sealed box are so compelling that, when he was visiting me to hear and measure the ESP Concert Grand SIs, John Atkinson was moved to query, “Why doesn’t everybody use sealed-box designs?” He then answered his own question: “Because nobody has ever gone broke selling a loudspeaker that booms.””_

my current 8 inch subs with 10 inch passive radiators are sealed and do a great job and arent boomy. But they only go to 40hz.

I don't think ive ever (knowingly) heard a bandpass box but they seem like they could be the best of both worlds. 

I should get bass box pro in the mail in a week or so. Ill try modelling with the free software ive got now and then see what bass box pro says.


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## dumdum (Feb 27, 2007)

Holmz said:


> Longer longeveirty from no dust?
> Or shorter from no cooling and more power?
> .
> 
> ...


Out of interest how do you think a dsp will deal with group delay? It generally goes up as the port takes over but is similar to sealed around the frequencys that are used for the crossover so a simple switch of time alignment will effect all frequencys and by putting one freq range in time you will take another out, all pass filters are not delicate enough for me and always cause issues for me


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## Holmz (Jul 12, 2017)

Sam Spade said:


> Multiple articles I've read claim that lack of ventilation of the box increases the risk of thermal induced failure of a sub. But it sounds like a dodgy claim to me. Never seen data on it.
> ...


Running 1kW to them is like a kettle or a blow dryer inside of it...
Where does that power that goes into heat end up? And how does it escape the box?




dumdum said:


> Out of interest how do you think a dsp will deal with group delay? It generally goes up as the port takes over but is similar to sealed around the frequencys that are used for the crossover so a simple switch of time alignment will effect all frequencys and by putting one freq range in time you will take another out, all pass filters are not delicate enough for me and always cause issues for me


With FIR the are not a lot of taps, so not a lot of resolution. 4K of taps give 5Hz resolution, and 10k gives 2-1/2... or maybe it is 10hz and 5Hz?.
Also someone posted some allpass work recently using IIR.
And one cannot attempt anything to mitigate it without a DSP!

Basically transcient response and group delay are good arguments against a bandpass, but with a DSP one has a chance. I only know that the Brax costs a lot... I dunno if it is capable of doing anything towards the problem?

I doubt that a person that wants a sealed box over a port box, would then want to try and jump to to a bandpass?

A test box would at least allow one to try and work through it.


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## OME573X (Apr 18, 2020)

I admittedly dont know much about Audio and I'm slowly learning.. but for my build I'm doing now, a SQ build in my daily driver I picked up a used Focal 33KX for roughly 300$... designing my trunk layout I am starting to wonder if I should have went with a pair of 10's like a Ultimo or AF... the expense being the biggest issue...

I havnt heard all that much about Focal as far as searching and such... in order to make my set up somewhat symmetrical I'd like to mount it in the center of the trunk towards the rear window but dont have the space... that and hearing a few guys saying that in a sealed enclosure in the trunk the 33kx leaves some "umghf" to be desired and had a few suggest even adding a shallow 8 in the cab...

Just curious what anyone's views are on this... I'll likely use the focal for now as I already have it, just curious if there's anyone with options on the KX line as apposed to some of the more frequently spoken of brands...

Suppose this should have it's own thread... still on the same idea of SQ subwoofers tho...

To mention a bit on Skar Audio I have heard great things from alot of local guys on there amps as well as subs for the cost... not something I was considering but I noticed there name coming up on this thread


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## Sam Spade (Mar 16, 2020)

Holmz said:


> Running 1kW to them is like a kettle or a blow dryer inside of it...
> Where does that power that goes into heat end up? And how does it escape the box?
> 
> With FIR the are not a lot of taps, so not a lot of resolution. 4K of taps give 5Hz resolution, and 10k gives 2-1/2... or maybe it is 10hz and 5Hz?.
> ...





Holmz said:


> Running 1kW to them is like a kettle or a blow dryer inside of it...
> Where does that power that goes into heat end up? And how does it escape the box?


I had not thought of it like that. But hopefully most of the energy is dissipated as sound and cone movement.



Holmz said:


> I doubt that a person that wants a sealed box over a port box, would then want to try and jump to to a bandpass?


It seems to me that bandpass might deliver the best of both worlds, tight defined bass i am seeking with the frequency extension and possibly greater SPL efficiency of a simple vented single box. But thats just a complete guess untill i start modeling or building and testing


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## Holmz (Jul 12, 2017)

Sam Spade said:


> I had not thought of it like that. But hopefully most of the energy is dissipated as sound and cone movement.
> 
> 
> It seems to me that bandpass might deliver the best of both worlds, tight defined bass i am seeking with the frequency extension and possibly greater SPL efficiency of a simple vented single box. But thats just a complete guess untill i start modeling or building and testing


Speaker are horribly inefficient. Hope does not cure it, but horns are waveguides help,

Bandpass only delivers if you can tame the group delay, and transcient response is not crucial. If transcient response is, then go IB, which is a first order.
You will need to build a cheap test box, and see if your DSP can get you there in terms of group delay.


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## Sam Spade (Mar 16, 2020)

Holmz said:


> Speaker are horribly inefficient. Hope does not cure it, but horns are waveguides help,
> 
> Bandpass only delivers if you can tame the group delay, and transcient response is not crucial. If transcient response is, then go IB, which is a first order.
> You will need to build a cheap test box, and see if your DSP can get you there in terms of group delay.


Just thinking out loud, and wondering if at least some of a sub box could be made of a good heat dissipating material, something like a metal heat sink. But in Oz that is more likely to just heat the box up more during summer.


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## Bayboy (Dec 29, 2010)

An ideal SQ sub is one that's linear with relatively low distortion though that's many in the market. If output without having to resort to gobs of power is a concern, I suggest a ported alignment augmented with EQ to tame the sum of it being in the vehicle. 

Not on most radars, but a Dayton HO single coil 10" is a very capable sub if used ported (it's great sealed when you're tight on space). The vent area is a little bit of work, but the extension in a fairly compact box would be worth it. Pairing two would make port work a bit easier. However, if you have lots of room you don't mind giving up, there's many subs that will suffice. It's not difficult to find something that works. It's just a matter of proper enclosure and tune. 

Sent from my SM-G986U using Tapatalk


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## Holmz (Jul 12, 2017)

Sam Spade said:


> Just thinking out loud, and wondering if at least some of a sub box could be made of a good heat dissipating material, something like a metal heat sink. But in Oz that is more likely to just heat the box up more during summer.


Just thinking out loud... why would you believe anything I post?
Just shove a thermometer into it and see.

Secondly a 1kW amp is probably only supplying 100W on average to the sub... but you could put an ampere meter on it and see what it gets, and then you would not have to believe what you read... you would just know.


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## Bayboy (Dec 29, 2010)

Might take some time to find, but if you search back to when the HO first gained popularity, you should see a thread where the 10" was tried sealed & ported on a mere 240 watts. The enclosure was around .7 cubes.

Sent from my SM-G986U using Tapatalk


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## cman (Aug 24, 2020)

ckirocz28 said:


> That joke about 9 feet of 6" inch pvc pipe was not so much a joke as it was inaccurate, 2 6" inch pvc ports 9 feet long for 1 SDX12 tuned to 25 hz with manageable port velocity is more accurate. For those subs, passive radiators are a much more realistic solution, but more expensive too.


Check this out, something like this triple enclosure for a Single CSS SDX12 plus two passive radiators. LOL, its actually almost perfect if you do a low tune. anything above 25hz it gets a nasty peak.... not sure how much weight you need on those radiators to achieve a 22hz tune in a 77 liter enclosure.. I dont know how to model PR's i know tuned super low ported I really like the response curve in Winisd but the port would have to be small and cause alot of noise without PR's, check out this picture.






BLACK 12" TRIPLE SEALED SUB BOX


Ground-shaker is a leading speaker box company in Southern and Northern California with an objective to strive into a worldwide speaker box company




www.ground-shaker.com













SHOP | css-audio







www.css-audio.com


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## gijoe (Mar 25, 2008)

Holmz said:


> This is a blanket statement...
> 
> Ported have lower distortion and make more SPL, so they do not require as much power.
> Ported and bandpass have higher group delay, but that could be addressed with a DSP.
> ...


You cannot fix the group delay of a ported box with DSP. The rear wave that exits the port will always lag behind the front wave. You can't fix that with DSP. That has to be counted as distortion since it is an unwanted addition to the original signal.


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## ckirocz28 (Nov 29, 2017)

gijoe said:


> You cannot fix the group delay of a ported box with DSP. The rear wave that exits the port will always lag behind the front wave. You can't fix that with DSP. That has to be counted as distortion since it is an unwanted addition to the original signal.


My sentiments exactly. Ported boxes are fun, but they tend to sound "off" compared to sealed boxes.


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## Holmz (Jul 12, 2017)

Maybe I can't but hanatsu seems to be able to do it.

And at some point the sound comes mostly out of the port... so I guess some lower level sound out of the front would be a distortion like pre ringing?

In any case the majority of the super low stuff has low group delay after the DSP magic.
It went from a high numbers of milliseconds, to low numbers... so it seems like it is better.




Hanatsu said:


> Re-visited an interesting feature with the Raspberry Pi4 and volumio OS. You can use bruteFIR as a plugin in Volumio, this allows for really high amounts of FIR-taps as the cpu power of the Raspberrry pi4 has reached desktop computer power (sort of).
> 
> https://github.com/balbuze/volumio-plugins/tree/master/plugins/audio_interface/brutefir3
> 
> ...


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## Sam Spade (Mar 16, 2020)

gijoe said:


> You cannot fix the group delay of a ported box with DSP. The rear wave that exits the port will always lag behind the front wave. You can't fix that with DSP. That has to be counted as distortion since it is an unwanted addition to the original signal.


Im pretty sure you've just described the reason that ported subs are considered boomy compared to sealed.


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## Holmz (Jul 12, 2017)

Sam Spade said:


> Im pretty sure you've just described the reason that ported subs are considered boomy compared to sealed.


Is it a lack of group delay EQ, or some bad amplitude EQ?


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## Sam Spade (Mar 16, 2020)

Interestingly my dalisuite 3.5s are -3db at 32 hz are ported in the front and have a smaller port at the back and presumably 3 chambers. One is sealed i think. But they've never sounded boomy. The bass reproduction is outstanding. Part of that is the rotel RB1080 200 wpc into 8 ohs damping factor 500 power amp. It grabs most speakers by the balls and controls them. I didn't get the same bass performance with my marantz PM80 which is a seriously good 100wpc into 8 ohms amp.

But the build qualty is amazing too. Really solid and rigid. Almost takes 2 people to move them.


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## Sam Spade (Mar 16, 2020)

Holmz said:


> Is it a lack of group delay EQ, or some bad amplitude EQ?


Two bass waves coming out of a sub at different times from the same input signal, aka _The rear wave that exits the port will always lag behind the front wave _be group delay wouldnt it?


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## Sam Spade (Mar 16, 2020)

I'm wondering though like with my Dalis, really good design and construction of a ported or bandpass could bring the performance of ported and sealed closer by making ported sound less boomy? You'd still have bass signals coming out at different times though?


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## CCole (Sep 9, 2020)

I completely agree with gijoe. From my understanding it is the polar opposite of the statement holmz made. Holmz please elaborate on your thought! I’ve been known to be wrong in the past. Ha In the highend home audio world. By highend I mean Wilson Audio, Magnico, Lamm, etc along with Dr. level Engineering Acoustics colleagues. The vast majority recommend plugging any ported subs in a dedicated 2-channel listening setup. The issues with an out of spec sealed enclosure are easier to overcome than the group delay natively built into the design of a ported enclosures. Sound waves are coming out of 2 locations on a ported enclosure and if they’re not in perfect alignment/timing that results in phase problems. 
Don’t get me wrong I love ported for the efficiency. Ultimately sealed is king for smooth transition between low to mid frequency’s in my opinion. My current SQ build has 2 enclosures the first is 2-15 FI SSD at 1ohm on 4000watts This is my fun box! The second is a single 13W7 sealed one amp per VC at 1.5 so 3000 watts available.The W7 is a quality piece for SQ. I bought the 13 & 12 needing cone jobs for $275. Many better sub choices for half the money of JL retail. The JL is also great for space saving road trips.


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## Holmz (Jul 12, 2017)

CCole said:


> I completely agree with gijoe. From my understanding it is the polar opposite of the statement holmz made. Holmz please elaborate on your thought! ...
> ...


I do not think they are polar opposite statements.
(And I usually agree with him as well.)

The sound out of the port is generally near the tuning frequency and the sound out the front higher frequencies.
And the port dominates in terms of SPL down low, and then they are qual, and at higher frequencies the port is quieter.

Maybe I am wrong, but one could work it out with a microphone and show the truth?

In any case... Hanatsu's English is better than mine, and I posted his quote from his build in my post #122.
And hid graphs show group delay being reduced from the DSP and his tuning.

So it would appear that a DSP can reduce group delay of a ported enclosure?


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## Holmz (Jul 12, 2017)

Sam Spade said:


> Interestingly my dalisuite 3.5s are -3db at 32 hz are ported in the front and have a smaller port at the back and presumably 3 chambers. One is sealed i think. But they've never sounded boomy.
> ...


To me the port suggests that something is using ported enclosure 
And there is a front and a back port...??

Since you do not like ported enclosures, I am wondering how you could like how those speakers sound 




Sam Spade said:


> I'm wondering though like with my Dalis, really good design and construction of a ported or bandpass could bring the performance of ported and sealed closer by making ported sound less boomy? You'd still have bass signals coming out at different times though?


I am not sure you even know how those Dalis are constructed?

But that is the whole point of modelling... i.e. to avoid a boomy box, and not drive it to over excursion, etc.

Maybe you can measure Dalis and tell us? I see speakers and I see a front port, and you said a rear port exists... so what are they doing? And how many acoustic signals are coming out? There has to be two, three, or more?




Sam Spade said:


> Two bass waves coming out of a sub at different times from the same input signal, aka _The rear wave that exits the port will always lag behind the front wave _be group delay wouldnt it?


Basically "NO". You probably need to look up what group delay is.

Group delay is a delay changes with frequency... so it has is nothing to do with two or more holes.
You would be better of think of a 6th order series bandpass, where one only have a single hole and no visible speaker to avoid confusing us as to where the sound is coming out... and not a dual bass reflex, where we have two holes.


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## Sam Spade (Mar 16, 2020)

Holmz said:


> To me the port suggests that something is using ported enclosure
> And there is a front and a back port...??
> 
> Since you do not like ported enclosures, I am wondering how you could like how those speakers sound
> ...



"_Since you do not like ported enclosures, I am wondering how you could like how those speakers sound_  " Dali make great stuff, I'm pretty sure there are 3 chambers, one for each 8 inch driver, one sealed and two ported to get different frequencies to integrate and a flat response.

It isn't that I don't like ported enclosures, Just that the subs I've heard I've preferred enclosed.

I definitely need a "car audio for dummies " book. I'm still on a steep learning curve.


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## Holmz (Jul 12, 2017)

Sam Spade said:


> "_Since you do not like ported enclosures, I am wondering how you could like how those speakers sound_  " Dali make great stuff, I'm pretty sure there are 3 chambers, one for each 8 inch driver, one sealed and two ported to get different frequencies to integrate and a flat response.
> 
> It isn't that I don't like ported enclosures, Just that the subs I've heard I've preferred enclosed.
> 
> I definitely need a "car audio for dummies " book. I'm still on a steep learning curve.


Your "just the subs I have heard..." statement is like saying the only swans I have seen are white?

You say you like the Dalis.
Your Dalis are ported.
You say you like sealed enclosures, and do not like ported enclosures?

You say you like your under the seat car subs.
Your under the seat car subs are 8" and use a passive radiator.
You say you prefer sealed enclosures over ported?

I can show you any number of subs and make them good or bad.

Probably more people have hosed up 4th order boxes than 2nd order boxes.
And 6th are hosed up more than 4th.
And 8th order more than 6th order.

The evidence is that you are willing to pay for ported enclosures, and you only want to "appear to like sealed"... but unwilling to actually pay for a sealed enclosure?


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## Sam Spade (Mar 16, 2020)

Holmz said:


> Your "just the subs I have heard..." statement is like saying the only swans I have seen are white?
> 
> You say you like the Dalis.
> Your Dalis are ported.
> ...


_Your "just the subs I have heard..." statement is like saying the only swans I have seen are white?_
That's not a good analogy. I've seen black and white swans and like the black ones better, but the white ones are still beautiful.
_
You say you like the Dalis.
Your Dalis are ported.
You say you like sealed enclosures, and do not like ported enclosures?_
The quality of Dali's R&D team means they can get awesome non-boomy bass in ported chambers. And they can put 3 chambers in the speaker using three 8 inch drivers and get an awesome result. One of the chambers might even be bandpass. I'd have to take them apart to check. That kind of design is way beyond my current ability and probably always will be.

In any case I said based on subs specifically I like sealed better. I didn't mention a preference for loudspeakers overall. 

_You say you like your under the seat car subs.
Your under the seat car subs are 8" and use a passive radiator.
You say you prefer sealed enclosures over ported?_
I don't have subs under my seats. They are under my false floor, and the hertz active passive sealed box sound great, but I think they are the weak link in my setup only going to 40 hz. Well the other weak link is my tuning ability which I'm working on. 

And yes the subs I've heard I've generally liked enclosed better. Having said that, I'm just talking about bass reflex. I'm not sure I've ever heard a bandpass design. 
_
I can show you any number of subs and make them good or bad._
Which is why knowing someone like you with loads more experience and knowledge is so unbelievably helpful. 

_Probably more people have hosed up 4th order boxes than 2nd order boxes.
And 6th are hosed up more than 4th.
And 8th order more than 6th order._
I'm not sure what hosed up means?
_
The evidence is that you are willing to pay for ported enclosures, and you only want to "appear to like sealed"... but unwilling to actually pay for a sealed enclosure?_
I'm not quite sure what you are getting at with this sentence. What I build will depend on the modeling to some extent. Also space considerations. My currently stated preference for sealed based on what I've listened to. And Brax saying: "_Regarding bassreflex enclosure - we do not recommend any BR systems for BRAX subwoofers. BRAX subs are designed for sealed enclosures and that's why you will not find any recommendation for vented systems on our website. Of course it will be possible to use the ML8 SUB in a BR enclosure, but this will lead to rather poor impulse response which does not meet our BRAX philosophy."_

I'm building my own boxes for my ML8 subs. I'l model designs first on bass box pro and winISD.The cost difference between ported and sealed is likely to be minimal.


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## Hanatsu (Nov 9, 2010)

Sam Spade said:


> Im pretty sure you've just described the reason that ported subs are considered boomy compared to sealed.


No. That is not the reason, mostly. In a minimum phase system, frequency response does have a phase response and a magnitude response that responds in proportion to each other. If you have bumps in the frequency response you will also have a "bump" in the phase response. Group delay is a derivative of frequency response. Any subwoofer, port or not that have a non-flat frequency response will have a non-flat group delay. 

Tall-order subwoofer systems like vented or multivented designs does indeed have higher group delay BECAUSE of the port but in the majority of cases this is NOT what people refer to. They react to the bump in frequency response that many vented designs tend to have, especially in cars (cabin gain) and especially if it's fabmade box with highish tuning frequency. A peak in the frequency response = peak in group delay. This delay peak can be in the order of magnitudes larger than any delay introduced by the port. 

I've used vented boxes exclusively while competing and people never suspect it's a vented 15", this is without any fancy processing, just good EQing. 

Deviations in frequency response = fixable with DSP (group delay included). These are forms of linear distortion. Acoustic nulls introduced in a non-minimum phase system is another matter though.

Non-linear distortion (Harmonic distortion and intermodular distortion for example) cannot be fixed with DSP. HD/IMD is cause by non-linearities in the motor/suspension etc and goes up with excursion. Sealed boxes are horrible in this regard, for the same SPL you need to have 4 times the cone travel with each decreased octave. Vented boxes can have almost zero excursion and yet higher SPL and higher efficiency. Vented designs tend to have higher linear distortion and much lower non-linear distortion if built correctly. They will objectively be better if you use phaseEQ. The only drawback would be "complexity" and physical size.


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## Holmz (Jul 12, 2017)

Sam Spade said:


> ...
> I'm not sure what hosed up means?
> ...


It is a Canadian phrase synonymous with the Aussie word, "rooted" or "cactus".
(Like the past tense of the F-bomb.)




Sam Spade said:


> ...
> _... Of course it will be possible to use the ML8 SUB in a BR enclosure, but this will lead to rather poor impulse response which does not meet our BRAX philosophy."_
> ...


^interesting^


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## Hanatsu (Nov 9, 2010)

Thought I add this as well.

Many tend to mix these up, we got "theoretical delay" as you can see in any somewhat competent modeling software and we got the actual acoustic delay, derived from the measured in-room impulse response. These are not the same.

Comments like "plug the port is better" is meaningless. You need to measure the room with a microphone and look at the minimum phase derived delay (excess group delay in REW). In lower frequencies, way below the modal transitional frequency (room dimension dependable), a single-point measurement will be good enough. There you can do a measurement to actually see what happens. If you have very few room modes (destructive interference), then a large proportion of the lower frequencies could be classified as minimum phase. Then frequency response would be the absolute number 1 to keep flat or at least even, this if your ultimate goal is to reduce delay. Then again, I think you'd be shocked to see how little this matters when you break it down. For home audio, the first thing to attack is room acoustics. Download rePhase, import measurements from RoomEQ, do some phaseEQ, run the output-IR through a VST to listen to the actual differences. You could create an inverse phase curve of the modeled phase response to remove the phase shift of the port from the equation. This will determine if it's really the port that's the issue. Unless it's just bad design, my bets is on that most people would define the change as "quite subtle". Correctly applied room correction is far from subtle though (in most cases).

Note that any type of active crossovers used in subwoofers etc will cause massive amounts of delay, as well. Many people who use subs with Fb in the 40Hz area also has their highpass turned on (also called subsonic for some reason). This makes the problem even worse. My point, blame the frequency response first hand, not the enclosure type.

edit, there was a good study on this particular matter but I can't seem to find it. I did find this one though that does something similar.

https://www.aes.org/tmpFiles/elib/20201025/19869.pdf


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## Sam Spade (Mar 16, 2020)

Hanatsu said:


> No. That is not the reason, mostly. In a minimum phase system, frequency response does have a phase response and a magnitude response that responds in proportion to each other. If you have bumps in the frequency response you will also have a "bump" in the phase response. Group delay is a derivative of frequency response. Any subwoofer, port or not that have a non-flat frequency response will have a non-flat group delay.
> 
> Tall-order subwoofer systems like vented or multivented designs does indeed have higher group delay BECAUSE of the port but in the majority of cases this is NOT what people refer to. They react to the bump in frequency response that many vented designs tend to have, especially in cars (cabin gain) and especially if it's fabmade box with highish tuning frequency. A peak in the frequency response = peak in group delay. This delay peak can be in the order of magnitudes larger than any delay introduced by the port.
> 
> ...


Subwoofers are clearly complicated. Which is why first time around i bought 2 hertz boxes with an active 8 inch, passive 10 inch low profile easy to install designed and built by experts. At that time i had multiple driver options but decided prefab by experts was more sensible. Whether or not i can achieve a better result than the experts at hertz building my own box with brax drivers is yet to be seen. But a cars worth of brax drivers and some C four helix amps landed in my lap legally at an insanely good price so i decided to bite the bullet and try and get a good result with what is pretty good gear, better than what i currently have anyway. Last build was stealth as i felt paranoid about stealing risk. Ive got past that now and with the right insurance ill be comfortable with a visible system not that i have any plans of building something showy. Its about the music not the appearance. But the more research i do the more contradiction and the less confident i am.

I also have brax telling me " _Of course it will be possible to use the ML8 SUB in a BR enclosure, but this will lead to rather poor impulse response which does not meet our BRAX philosophy."_"

Given all this for a beginner looking to build a sub with two brax ML8 sub drivers, winISD and bass box pro with plenty of amplification and space, brax having a clear opinion on ports and all the other sources i read having wildly different opinions and seemingly lots of people writing on the topic that contradict each other and don't understand it, well what would your advice be Hanatsu?

I'm not seeking insane volume levels. I just want a balanced system where the sub, midbass, and front stage are balanced and integrared. This comment of yours compellingly suggests i should avoid sealed and go for bass reflex: " _Sealed boxes are horrible in this regard, for the same SPL you need to have 4 times the cone travel with each decreased octave. Vented boxes can have almost zero excursion and yet higher SPL and higher efficiency." _Oh and i knew ported is more efficient and had better extension but no-one ive read explained it as clearly and emphatically as you.
You are clearly an expert on this and can build ported boxes and get an excellent result. Is this beyond mere mortals or can a beginner building his first sub get a good result with ported?
Is there a single reference source that i can rely on? I'm hoping that when bass box pro arrives with it's lengthy manual that could be it.
How do you reconcile brax's position on sealed boxes
Thanks
Sam


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## Sam Spade (Mar 16, 2020)

Hanatsu said:


> Thought I add this as well.
> 
> Many tend to mix these up, we got "theoretical delay" as you can see in any somewhat competent modeling software and we got the actual acoustic delay, derived from the measured in-room impulse response. These are not the same.
> 
> ...


given the contradictions across the internet and even just within this thread, you are the person that has most emphatically explained the theory and practice of sub performance that I have read Hanatsu. You appear to have understanding of the topic, not just opinions. I think I'll consider you my guru


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## Hanatsu (Nov 9, 2010)

Sam Spade said:


> Subwoofers are clearly complicated. Which is why first time around i bought 2 hertz boxes with an active 8 inch, passive 10 inch low profile easy to install designed and built by experts. At that time i had multiple driver options but decided prefab by experts was more sensible. Whether or not i can achieve a better result than the experts at hertz building my own box with brax drivers is yet to be seen. But a cars worth of brax drivers and some helix amps landed in my lap legally at an insanely good price so i decided to bite the bullet and try and get a good result with what is pretty good gear, better than what i currently have anyway. Last build was stealth as i felt paranoid about stealing risk. Ive got past that now and with the right insurance ill be comfortable with a visible system not that i have any plans of building something showy. Its about the music not the appearance. But the more research i do the more contradiction and the less confident i am.
> 
> I also have brax telling me " _Of course it will be possible to use the ML8 SUB in a BR enclosure, but this will lead to rather poor impulse response which does not meet our BRAX philosophy."_"
> 
> ...


The term "Impulse response" is very loosely thrown around. The slope of a impulse response (how steep it is, the "faster it looks") is actually high frequency content. It's completely ridiculous to use it in a pure subwoofer measurement and apply terms as "poor performance". What they most likely refer to is group delay and the vented box have worse performance in that regard by design, out of the box without DSP. For the non-enthusiast and also in the audiophile-scene, DSPs are not very popular. It's easier to make a claim that you should use a sealed box for SQ, heard it a million times. It's hard to mess up building one, volume size doesn't matter as much, a Qtc 0,7 box kind of rolls off at 12db/oct below -f3 which 'kind of' match the transfer function of the average car (cabin gain). People that buy it will be satisfied with how it sounds with little effort made and Brax maintains their reputation as a high-end product. That's my take.

You need to consider that the driver in question might be designed for a specific enclosure type. High Qts, low Fs drivers tend to work good in sealed boxes and low Qts and mid Fs tend to be better for vented (just generally speaking). If a driver works good for sealed, then 4th order bandpass is an excellent alternative. It's basically a sealed box inside a vented box and takes advantage of both types. Downside is again, size.

All readily available modelling software relies on low signal T/S parameters. If you don't measure these yourself with some equipment like DATS/WT3 they are likely to be incorrect by some degree. Some manufacturers are better than others, values could differ as low as 5% but also up to 50% in some extreme cases. Not to derail too much but things like ambient temperature and high excursion alters T/S parameters which is used to optimize the enclosure. When the cone travels farther away from the resting position the electromagnetic field weakens and alters a bunch of other interconnected parameters. A sealed box will be affected more of these changes since it's required to have a larger excursion range than a speaker designed for vented designs but at the same time, a sealed box isn't very picky, the response won't change that much. These changes become more and more important when you build taller order bandpass designs where the room for error is extremely low.

I've used very expensive subs years back, but now I use a cheap $40 GAS sub in a vented box in my daily driver and managed to squeeze out amazing performance out of it. Even some of my audiophool friends says it sounds impressive. In my opinion you need a large port, with dual flanged ends, no air restrictions and sharp edges anywhere around the vent. Keep the air velocity low for good performance (the vent can introduce distortion and noise). I dampen the vent internally if it's a standard plastic aeroport with "dynamat"-similar stuff, lots of internal braces. Overdimension the walls and never use wood screws to fasten the subwoofer. I take some care not to couple the sub directly to the car's chassis by using something soft between the box and the floor, it helps. While tuning it's very important to EQ the sub and midwoofers to the same level around the crossover region, use time alignment or some phase adjust to fix cancellation issues around the crossover region. You can T/A the fronts to maximum delay to allow the sub to match up better but don't overdo it, some DSPs allow really high delay adjustments. Tuning and the construction of the box is probably more important than the subwoofer itself to some extent of course. Some speakers are just trash, but you certainly don't need high-end subwoofers for SQ, imho.


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## cman (Aug 24, 2020)

This is all over my head but I will add this... I always thought sealed was the only way to go if you were interested in SQ. Andy @ Audiofrog mentioned multiple times that ported can be just as "SQ" in a car as sealed IF done correctly. I do not think Andy "All knowing expert" like some think, but I do believe he is damn good at what he does and all the products I've got from him are a step above the rest to say the least... So Him bringing that up in discussion is the actual reason I decided to take the plunge and try a ported enclosure...

I'm still working on the enclosure and what sub to get.... I want something clean, but not too clean. I was almost ready to pull the trigger on a brahma but i read multiple things about them being too clean and not sounding as loud due to the extremely low distortion. I might just have to spend the extra coin and get two GB12's. The only reservation I had about a single GB12 was the 600 watt RMS rating. I get a little trigger happy with the volume sometimes and I was concerned about smoking it (1400 rms amp). Two would suffice but be twice the cost


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## Holmz (Jul 12, 2017)

Tak @Hanatsu


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## Sam Spade (Mar 16, 2020)

Hanatsu said:


> The term "Impulse response" is very loosely thrown around. The slope of a impulse response (how steep it is, the "faster it looks") is actually high frequency content. It's completely ridiculous to use it in a pure subwoofer measurement and apply terms as "poor performance". What they most likely refer to is group delay and the vented box have worse performance in that regard by design, out of the box without DSP. For the non-enthusiast and also in the audiophile-scene, DSPs are not very popular. It's easier to make a claim that you should use a sealed box for SQ, heard it a million times. It's hard to mess up building one, volume size doesn't matter as much, a Qtc 0,7 box kind of rolls off at 12db/oct below -f3 which 'kind of' match the transfer function of the average car (cabin gain). People that buy it will be satisfied with how it sounds with little effort made and Brax maintains their reputation as a high-end product. That's my take.
> 
> You need to consider that the driver in question might be designed for a specific enclosure type. High Qts, low Fs drivers tend to work good in sealed boxes and low Qts and mid Fs tend to be better for vented (just generally speaking). If a driver works good for sealed, then 4th order bandpass is an excellent alternative. It's basically a sealed box inside a vented box and takes advantage of both types. Downside is again, size.
> 
> ...


Hey Hanatsu, i forgot to say *thank you so much for being so generous* with your time and knowledge in these posts. Both your theoretical knowledge and practical advice. I really appreciate it. You should write a book 😄

_Non-linear distortion (Harmonic distortion and intermodular distortion for example) cannot be fixed with DSP. HD/IMD is cause by non-linearities in the motor/suspension etc and goes up with excursion. Sealed boxes are horrible in this regard, for the same SPL you need to have 4 times the cone travel with each decreased octave._

This might be a dumb question but might it be that audiotech fischer believe that their sub drivers are so well designed and built that _non-linearities in the motor/suspension etc_
are not an issue for them? Or are non lineralities inevitable however good the construction and design?

_ The term "Impulse response" is very loosely thrown around........ What they most likely refer to is group delay _

In brax's case i wonder if this impulse response/group delay term usage is a result of english being a 2nd language for germans? But you could be right, if it is hard to stuff up a sealed box and easy to stuff up a ported one, then taking the line they have is the safe one, even if it doesn't maximise potential performance.

_ For the non-enthusiast and also in the audiophile-scene, DSPs are not very popular. _

That's interesting, on this forum people are fanatical about DSPs. But despite having a strong background in home and headfi, and having sold hifi in the early 90's while I was at Uni, 9 months ago I didn't even know car DSPs existed let alone how important they are. And now I have a helix ultra and I am wrestling with its not very intuitive software  But this is also the first time I've done carfi properly, historically I have just replaced the OEM head unit with an Alpine or similar, replaced the front speakers and driven around with the fader all the way forward.


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## Bayboy (Dec 29, 2010)

Designing a well-executed vented sub is not hard and can be quite rewarding. However, as Hanatsu suggests, there's optimal and suboptimal choices of subs for the design as well as the type of alignments that nets a certain response. Same differences as sealed. Such info is available in Vance Dickason's LDC series which is a good read. Add to that, room gain or better still, the actual measured acoustics of your vehicle augmented with EQ. 

Sounds like a lot, but it actually isn't. Just don't start out with any sub and decide on what type of enclosure you want. Realize your target, that may include box size, tuning, and response (flat tends to be better), then choose accordingly while avoiding build issues like complex vent lengths, exceeding vent velocity before achieving desired output, etc. Most decent modeling programs will help in that area. Again, it's really not hard at all. 

Sent from my SM-G986U using Tapatalk


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## Holmz (Jul 12, 2017)

Sam Spade said:


> ...
> This might be a dumb question...
> ....







Sam Spade said:


> ...
> This might be a dumb question but might it be that audiotech fischer believe that their sub drivers are so well designed and built that _non-linearities in the motor/suspension etc_
> are not an issue for them? Or are non lineralities inevitable however good the construction and design?
> ...
> ...


What audiotech fischer believes is between them an God.

The Germans almost has a 1000 year reich over the rest of us. They are not generally considered idiots, except by people that they conquer.

They are probably loose with science and engineering and liberal with marketing.


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## Bayboy (Dec 29, 2010)

There's no fluff in the usage of those terms (group delay, etc). You have to remember that many buying Audiotec Fischer and associated gear are quite involved in making sure all aspects of system design are covered regardless how miniscule it may seem to the average person. Is it that detrimental? Debatable, but most of us obsess about other parts that may seem over the top. At least they're covering such a topic vs a company that just sells gear with barely any info. 

Sent from my SM-G986U using Tapatalk


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## gijoe (Mar 25, 2008)

Sam Spade said:


> Im pretty sure you've just described the reason that ported subs are considered boomy compared to sealed.


To be clear, I went from running subs IB in my Subaru, to a ported box in my Golf. I've got the box tuned low (28hz), and it certainly doesn't sound boomy. Just because you can't do much about the group delay doesn't mean that it will be a real problem. Although I would rather be running IB if I could, I am still very satisfied with the bass I get out of this ported box.


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## Holmz (Jul 12, 2017)

gijoe said:


> To be clear, I went from running subs IB in my Subaru, to a ported box in my Golf. I've got the box tuned low (28hz), and it certainly doesn't sound boomy. Just because you can't do much about the group delay doesn't mean that it will be a real problem. Although I would rather be running IB if I could, I am still very satisfied with the bass I get out of this ported box.


It is shown to be possible to correct the group delay.

It is hard to make an argument against IB impulse response, group delay, and wattage.


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## Holmz (Jul 12, 2017)

Bayboy said:


> There's no fluff in the usage of those terms (group delay, etc). You have to remember that many buying Audiotec Fischer and associated gear are quite involved in making sure all aspects of system design are covered regardless how miniscule it may seem to the average person. Is it that detrimental? Debatable, but most of us obsess about other parts that may seem over the top. At least they're covering such a topic vs a company that just sells gear with barely any info.


It ^this^ in response to my post?

They (AudioF) are wise to say, "use then sealed" because "impulse response".

And we would be wise to consider that they (AudioF) have specs. But we would also be unwise to believe that they (AudioF) somehow have a new speaker that is not fundamentally the same solid 50-100 design as everyone else uses with some minor emphasis here or there.
If their subwoofers were part of a system, then it would more likely that they were optimised in some powerful R&D way. So their saying use a x ft^3 sealed box is safe.
Those Hertz passive under the seat jobs, have more of a systems approach to them.


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## Bayboy (Dec 29, 2010)

Holmz said:


> It ^this^ in response to my post?
> 
> They (AudioF) are wise to say, "use then sealed" because "impulse response".
> 
> ...


But those minor differences are what some obsess about as I pointed out earlier. I was one of those types years ago.. tweaking sub & box combo to the tee, then confirming with sweeps. Lol yeah I was bit anal back then but felt it was justified in extracting the exact performance desired. At the same time, I didn't have the DSP power available today though there's still currently some that rather skip the use of for whatever reason. 

Sent from my SM-G986U using Tapatalk


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## Sam Spade (Mar 16, 2020)

Bayboy said:


> Designing a well-executed vented sub is not hard and can be quite rewarding. However, as Hanatsu suggests, there's optimal and suboptimal choices of subs for the design as well as the type of alignments that nets a certain response. Same differences as sealed. Such info is available in Vance Dickason's LDC series which is a good read. Add to that, room gain or better still, the actual measured acoustics of your vehicle augmented with EQ.
> 
> Sounds like a lot, but it actually isn't. Just don't start out with any sub and decide on what type of enclosure you want. Realize your target, that may include box size, tuning, and response (flat tends to be better), then choose accordingly while avoiding build issues like complex vent lengths, exceeding vent velocity before achieving desired output, etc. Most decent modeling programs will help in that area. Again, it's really not hard at all.
> 
> Sent from my SM-G986U using Tapatalk


Thanks bayboy, that's informative and inspiring  I'm feeling more confident.


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## mattjk (Apr 7, 2011)

Hanatsu said:


> extremely low.
> 
> I've used very expensive subs years back, but now I use a cheap $40 GAS sub in a vented box in my daily driver and managed to squeeze out amazing performance out of it. Even some of my audiophool friends says it sounds impressive. In my opinion you need a large port, with dual flanged ends, no air restrictions and sharp edges anywhere around the vent.


May I ask what this $40 sub is that you speak of? ;-)


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## Holmz (Jul 12, 2017)

mattjk said:


> May I ask what this $40 sub is that you speak of? ;-)


I think the graphs showing what the raspberry Pi's EQ are doing, may be responsible for some of the reason that the 40€ sub sounds good? 

I doubt that anyone can run just the 40€ sub on its own, and expect the group delay to be near zero.
Which was the reason i quoted the link.


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## Hanatsu (Nov 9, 2010)

mattjk said:


> May I ask what this $40 sub is that you speak of? ;-)


Cheapest stuff they got. I bought two on black friday for $40. Beat104 I think. Don't get me wrong, it's amazing quality for that kinda money...

Skickat från min SM-G960F via Tapatalk


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## Hanatsu (Nov 9, 2010)

Holmz said:


> I think the graphs showing what the raspberry Pi's EQ are doing, may be responsible for some of the reason that the 40€ sub sounds good?
> 
> I doubt that anyone can run just the 40€ sub on its own, and expect the group delay to be near zero.
> Which was the reason i quoted the link.


That not a measurement of the sub and not even the same car. It's not the raspberry pi either, I ran it through a VST on my computer laptop in my main project car. The pi4 isn't installed yet, only tested it on the bench. I only have access to 5 band parametric EQ in my daily driver and that's usually enough to get decent results out of a sub if you combine it with some clever crossover trickery...

Edit, here's the FR of my cheap sub with some EQ.



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## mattjk (Apr 7, 2011)

Hanatsu said:


> Beat104


Thank you! I love trying out budget stuff.


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## Clvol1255 (Aug 6, 2020)

JL audio makes as good as any when it comes to subs in that price range


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## Holmz (Jul 12, 2017)

Well back onto what the title suggests...
One of the main reasons to choose a SQ sub with low distortion would be in one needed to cross them over higher.

If the harmonic distortion is high, then that typical 80Hz XO point will have louder 160 and 240 Hz components.
Using a sub with a lower distortion will have those harmonics lower and more easily facilitate running a higher XO point without localising the subs.

So IB, ported and bandpass would all win in that scenario of moving the XO point higher in frequency.

Of course there is not a lot of room in a car, so sealed has an advantage in that respect. And they are only a bit harder than IB in construction.


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## Bayboy (Dec 29, 2010)

There's basically two trains of thought when it comes to choosing & manipulating a sub. Those that try to control every aspect of response by sub parameter & box combo, and others that rely on electronic augmentation. Neither are wrong, but using both is optimal in my book. After all, the best to me is one that needs less electrical manipulation to play as desired leaving more DSP power to account for acoustics of the environment. No less the same as striven for mids & tweets. 

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