# Stevens Audio MB-8 4 ohm Impressions



## DeLander

Hi all. I’m not sure if I should post this here or in the Reviews section, so please move it if need be. 
Special thanks to Eric for these. They are very hefty, solid and well built. I don’t notice anything odd with them ( like too much glue, anything misaligned, scratched, etc ). In other words, awesome Christmas presents from my family. 
I chose the 4 ohm drivers because I’m powering them with a PPI Phantom P900.4 bridged. This will provide approximately 400 w/ch @ 4 ohms. That should do it I think. 
The MB-8s are replacing Beyma 8BR40/N midbasses. The Beymas were installed for a little over a year. The driver’s side midbass went kaput on me about 2 months ago, hence the need for replacement. So I set out on a quest to find something beefier and hopefully more tolerant of my heavy volume finger?. 
After contacting several members here through PMs, I settled on the new Stevens Audio drivers. Being on a pretty limited budget, the MB-8s are priced within reason and are easy to acquire. All you need to do is get ahold of Eric or just order them through his Facebook page. 
Anyway, I modified my billet aluminum mounts the other day to accommodate the mounting bolt hole pattern. These mounts were originally made to hold pretty much ant 8” midbass with only mounting hole modifications needed. 
The aluminum mounts are attached to heavily deadened doors. There is a 1/8” rubber gasket and 3/8” insulating foam between the aluminum and metal door panel. There is also the same foam between speaker driver and aluminum mounts. 
I turned the amplifier gains on the P900.4 all the way down before powering up. I probably didn’t need to, but I figured better safe than sorry. 
I turned the levels on all other speakers all the way down by my P880PRS H/U so I could just get a feel for the MB-8s performance and response to volume increases. From what I can tell by ear, the P880 will go full volume on the knob without distorting or clipping. So, I slowly increased the volume while listening to a very familiar CD ( Rush - Moving Pictures ). The MB-8s took the full volume of my H/U with no problems with the amp gains reduced. 
I increased the H/U levels for the other speakers in my system until I got a pretty good blend with the MB-8 drivers by ear. This left the tweeters, midranges, and sub at considerably lower levels than previously. But, I didn’t want to get too carried away with power to the Stevens Audio drivers considering they’re not broken in yet and it’s only about 28 degrees here. 
To finish up this preliminary review, all I can say is that I’m pretty impressed with these new midbasses from Eric. They aren’t broken in yet, but they already have good bass and drum range punch. They also have the capability to play well into the upper midrange frequencies if needed. 
I will post some updates tomorrow after some more adjusting / listening time. But, so far, a big ?. Thanks again Eric.


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## DeLander

http://www.diymobileaudio.com/forum/attachment.php?attachmentid=202442&stc=1&d=1514345450
http://www.diymobileaudio.com/forum/attachment.php?attachmentid=202450&stc=1&d=1514345450
http://www.diymobileaudio.com/forum/attachment.php?attachmentid=202458&stc=1&d=1514345450


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## jamesjones

Did you happen to get the mounting depth?


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## DeLander

Yes. Mounting depth on these is 3.5”


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## DeLander

http://www.diymobileaudio.com/forum/attachment.php?attachmentid=202466&stc=1&d=1514346246
http://www.diymobileaudio.com/forum/attachment.php?attachmentid=202474&stc=1&d=1514346246
http://www.diymobileaudio.com/forum/attachment.php?attachmentid=202482&stc=1&d=1514346246


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## dcfis

That's my type of driver! Are you using them as a Midbass only? What else are you using for front stage? 

Anybody wang the 6.5s?


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## DeLander

http://www.diymobileaudio.com/forum/attachment.php?attachmentid=202490&stc=1&d=1514346543
http://www.diymobileaudio.com/forum/attachment.php?attachmentid=202498&stc=1&d=1514346543

Sorry, but this is the only way I can figure to post pictures from my phone?


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## DeLander

dcfis said:


> That's my type of driver! Are you using them as a Midbass only? What else are you using for front stage?
> 
> Anybody wang the 6.5s?


Yep. Midbass only-well-kinda sorta. 
My H/U is only designed for 2-way front stage + sub. I’m kind of fudging the crossovers right now between H/U and amps. 
Tweeters are Rainbow CAL25
Midranges are Faital Pro 3FE25
Midbasses are these Stevens MB-8
Sub is Alpine SWS-15D2
Amps are PPI P900.4 for midbasses
PPI P1000.1 for sub
ARC XXK4050 for tweeters and midranges


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## dcfis

Thanks man, awesome set up


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## DeLander

Thanks. I just wish there was somebody around here that could help with tuning it. I’m getting to the point where I’ll be able to start taking measurements as soon as the MB-8s are broken in a bit. I’ve never done it before so I’m a little apprehensive about the whole thing. I’ve only been tuning by ear so far, it’s the best sounding system I’ve ever had. But, I know it could get better with the proper tuning.


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## Elgrosso

Wow, that’s some serious baffle! 
Do you think you could chamfer it a bit inside?


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## DeLander

http://www.diymobileaudio.com/forum/attachment.php?attachmentid=202474&d=1514346242

If you notice in this picture, there actually is a 7.5” counterbore insid the mounting surface that is .625 deep to accommodate larger basket diameters. I tried to plan ahead for these kinds of things when I made them?


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## Elgrosso

I see, they’re really cool. But I was more thinking about “curving” the internal cylinder the maximum so they could breath a bit more. But I guess it’s limited by the door opening.


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## DeLander

Elgrosso said:


> I see, they’re really cool. But I was more thinking about “curving” the internal cylinder the maximum so they could breath a bit more. But I guess it’s limited by the door opening.


Oh. You’re talking about where they are mounted to the door surface. I already had to open the factory door hole around .75-1” all the way around to get it bigger than the baffle bore. I really don’t want to take any more off.


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## dsquared

Checked FB... only 98 bucks each. Might be worth a shot pending some further reviews.
Keep breaking those things in man .


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## DeLander

dsquared said:


> Checked FB... only 98 bucks each. Might be worth a shot pending some further reviews.
> Keep breaking those things in man .


Planning on getting more listening time today. Going to work on putting foam padding on the backs of my plastic door panels too. ( Don’t laugh-we have had it laying around for a couple years, and I think it will work well as a type of MLV replacement. At least it’s worth a try for free ).
I have a general question/concern. I’m not sure if it’s substantiated. 
Will cold weather adversely effect the speaker ? IOW, could it be damaged quicker if running at high volume before it’s “warmed up”? The high temperature is supposed to be in the low 20s here today.


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## Eric Stevens

DeLander said:


> Planning on getting more listening time today. Going to work on putting foam padding on the backs of my plastic door panels too. ( Don’t laugh-we have had it laying around for a couple years, and I think it will work well as a type of MLV replacement. At least it’s worth a try for free ).
> I have a general question/concern. I’m not sure if it’s substantiated.
> Will cold weather adversely effect the speaker ? IOW, could it be damaged quicker if running at high volume before it’s “warmed up”? The high temperature is supposed to be in the low 20s here today.


The cold temperature will change the compliance to some degree which would raise the Fo of the driver slightly rducing extension on the bottom end.

After listening for a while they will warm up, spider and surround will warm from the motion/flexing and the motor and basket will warm from the heat generated by the voice coil. the length of time for that is dependent on how much metal is in your speaker baffles and the time needed to warm those up but that will mostly pull heat out of the basket.

If you have the heater on in the car that wil help immensly.

As for damaging them, the temperature itself wont do anything, nor will the reduced compliance unless at full tilt boogey. If you dont hear distortion you are ok.


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## DeLander

Sweet. Thank you Eric. That’s what I thought, just needed informed conformation.


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## DeLander

I went out earlier, started the truck, and just let the system play for an hour or so at medium volume to warm up a bit. 
I then turned the midbass amp gains up to roughly where they need to be and gave it a listen with all other Speaker levels back up around where they were before. 
At moderate to moderate/loud volumes, the MB-8s sounded really good. They had even better midbass punch and impact than yesterday. However, at higher volumes they sounded- I don’t know how to describe it- shrill maybe, in the midrange. Almost like what I think “ringing”, that people talk about, would be. I’m not sure if this is just because they’re still not broken in yet or not. Maybe it’s a tuning issue. Could it be the aluminum baffle mounts causing this?
I’m going to let it play some more now and see what happens. I’m just a little apprehensive to put too much power/volume to them after what happened to my Beyma. We’ll give her a go !


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## Iamsecond

I think I know what your talking about. I had that happen with my si 65 on certain songs and after measuring with a mic I found the frequency that was causing it. I pulled it down a little bit and it never did it again. Probably a good idea to get a look at the frequency graph to see if there is a peak when you hear it. Just a thought.


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## DeLander

Good point. Like I said, this is all just kinda preliminary thoughts while breaking these in some. I do remember, after one of my Beymas went out, that I dropped around 800 Hz I think and it made a noticeable improvement. I’ll have to try some EQ adjustments here in a few. The system has been running now for around an hour. I guess it should be warmed up now?


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## Eric Stevens

DeLander said:


> I went out earlier, started the truck, and just let the system play for an hour or so at medium volume to warm up a bit.
> I then turned the midbass amp gains up to roughly where they need to be and gave it a listen with all other Speaker levels back up around where they were before.
> At moderate to moderate/loud volumes, the MB-8s sounded really good. They had evenbetter midbass punch and impact than yesterday. However, at higher volumes they sounded- I don’t know how to describe it- shrill maybe, in the midrange. Almost like what I think “ringing”, that people talk about, would be. I’m not sure if this is just because they’re still not broken in yet or not. Maybe it’s a tuning issue. Could it be the aluminum baffle mounts causing this?
> I’m going to let it play some more now and see what happens. I’m just a little apprehensive to put too much power/volume to them after what happened to my Beyma. We’ll give her a go !


What are your crossover points, and slopes and any other adjustments to help understand the setup, also what type of music was the most prevalent with 

Shrill in the mid-range is the 2 to 3 Khz range. I am thinking you are crossing over to your Faital Pro 3FE25 at 400 to 500 Hz so is it possible that the problem from the Faitals?

It is possible to have a cancelation at or above the crossover frequency causing a large dip making the midrange sound thin and shrill.

Anyways with some more data I can help you tune and improve it


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## DeLander

Thanks for the response Eric. 
Due to only having only my Pioneer P880PRS and amp crossovers to set with, the midbasses are actually running 80 to 1250 Hz both @ 24 dB slopes. The Faital midranges run from there up to a LP on the ARC XXK4050 @ 4K Hz and the tweeters are HP on the ARC @ around 5k Hz. 
This “ringing” was only noticeable with the Mb-8s running alone. Once I brought the other drivers up in levels, the sound was no longer noticeable, but I guess it was still there. 
The only thing I really listened to was Rush’s Moving Pictures. 
Thanks in advance to anyone for help figuring this out.


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## Elgrosso

Could it be something in the door not tightened enough?


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## DeLander

Elgrosso said:


> Could it be something in the door not tightened enough?


Don’t think so. The only things it could be are the bolts holding the mounts to the door. And those are tight- used another Christmas present on them- cordless impact drill !
And it doesn’t sound like a vibration. It’s more like a highish pitched ringing sound. It’s a piercing sound.


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## Eric Stevens

Just for thought process, When you play only portions of the music like that it can be hard to know if it sounds correct or not.

I prefer to use a vocal or simple instruments when trying to listen to drivers in isolation.

The RTA or other measurement of frequency response would be very helpful also.


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## lurch

Sorry to barge in , 
Eric, are there any canadian outlets that might have these ?
I really want a set. 
Currently running rockford pro 8's , 4 ohm, but feel i could do better and have been 
Watching the threads here on diy. 
Mounted in sturdy suburban doors, infinite baffle style. 
send me a private message if this doesn't belong here, thanks.


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## DeLander

I’m going to get more seat time today. Have a few errands to run. I’ll try listening to some vocals or simple instrumentals like you mentioned Eric
Like I mentioned before tho, it is kinda weird that I can’t hear this sound when all drivers are playing. I’m guessing the midranges are masking it.


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## Eric Stevens

lurch said:


> Sorry to barge in ,
> Eric, are there any canadian outlets that might have these ?
> I really want a set.
> Currently running rockford pro 8's , 4 ohm, but feel i could do better and have been
> Watching the threads here on diy.
> Mounted in sturdy suburban doors, infinite baffle style.
> send me a private message if this doesn't belong here, thanks.


No you would purchase directy from us here in ther USA for now. I will send my contact info by private message.


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## Eric Stevens

DeLander said:


> I’m going to get more seat time today. Have a few errands to run. I’ll try listening to some vocals or simple instrumentals like you mentioned Eric
> Like I mentioned before tho, it is kinda weird that I can’t hear this sound when all drivers are playing. I’m guessing the midranges are masking it.


The shrill sharp sounds might be something that is supposed to e there but doesnt sound right without the other frequency ranges being played.


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## DeLander

Well, I just popped in my IASCA test disk. I discovered a problem I hadn’t noticed before. I’m getting left and right channel sound out of both midbasses. I have to have my RCA cables screwed up somewhere between the H/U and amp. AGGGHHH
WEIRD that I hadn’t noticed it before. Changing “Listener Position” from Front to Left or Right in the H/U menu shouldn’t affect this should it ? I don’t think so.


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## DeLander

Good news. 
I got the RCA cables figured out. Not sure how I managed it, but I had lefts & rights connected to each side?
Anyway, that took care of that high pitched sound coming out of the MB-8s. So, if you’re thinking about getting these, do it. My problem was definitely operator error!!
I went through the entire IASCA CD. Everything sounds really,really good except my stage pulls to the left of center, closer to the left midrange/tweeter than the center of the dash. I’m assuming that I should correct this by H/U level adjustments. Correct ? Or is it a T/A adjustment?


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## SkizeR

DeLander said:


> Good news.
> I got the RCA cables figured out. Not sure how I managed it, but I had lefts & rights connected to each side?
> Anyway, that took care of that high pitched sound coming out of the MB-8s. So, if you’re thinking about getting these, do it. My problem was definitely operator error!!
> I went through the entire IASCA CD. Everything sounds really,really good except my stage pulls to the left of center, closer to the left midrange/tweeter than the center of the dash. I’m assuming that I should correct this by H/U level adjustments. Correct ? Or is it a T/A adjustment?


Could be either, or even both. Gotta take measurements to find out

Sent from my SM-G950U1 using Tapatalk


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## DeLander

I got a PM from Eric checking on these in my truck. It occurred to me that I hadn’t posted any updates in a while. It’s not scientific or anything, but here ya go. 
In comparison to the Beymas that they replaced, the MB-8s are definitely more detailed and “open” sounding. They aren’t as warm or heavy sounding as the Beymas. They have a more punchy kick type of sound, than a booming bass sound. This doesn’t mean the Beymas were boomy, just thicker sounding I guess. 
Again, remember, these 2 sets of drivers have identical installs, low and forward in my front doors. I’d really like to see how the MB-8s do in either sealed or ported enclosures.


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## lurch

Installed my mb8s today, the 2 ohm version that Eric recommended. 
They replace rockford fosgate 8" pros and they bolted right in, except that i wanted
to use the RF metal covers, this meant opening the holes behind the gasket on the 
Mb8's. There are 8 holes available on the basket if you are willing to carefully drill or
carve the front gasket away where the holes are hiding. 

First impressions : 
well boxed, no frills, just these beautiful speakers that scream quality. 

Installation was EZPZ in my case, they were both up and playing in less than 20 minutes. 

SOUND :
Unfortunately the weather turned suddenly today, below freezing and a chill wind then
blankets of snow. 
So not much listening today, maybe eight tracks 
The stereo separation is MUCH better, probably because these reach into the 4k range
smoothly. 
These easily keep up with the rest of my equipment now, it's nice to hear loud and clear
and sterephonic music ! ( sometimes scaring the crap outta me with left & right info ). 
The sound is now " effortless ", and open, nice & tight too. 

No time to play with EQ today or anything else, but so far i like what i hear. 
This is a big step up from the rockfords. 

I hope that they loosen up, right now they are hardly moving and this is on approx 
150 watts. Again, they have only played for about half an hour. 

Thankyou Eric ! 
You were very patient with me and took the time to accommodate me. 
Service like this is always remembered and valued. 

I'll post again with an update once these loosen up and have played for a few days.


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## Eric Stevens

lurch said:


> Installed my mb8s today, the 2 ohm version that Eric recommended.
> They replace rockford fosgate 8" pros and they bolted right in, except that i wanted
> to use the RF metal covers, this meant opening the holes behind the gasket on the
> Mb8's. There are 8 holes available on the basket if you are willing to carefully drill or
> carve the front gasket away where the holes are hiding.
> 
> First impressions :
> well boxed, no frills, just these beautiful speakers that scream quality.
> 
> Installation was EZPZ in my case, they were both up and playing in less than 20 minutes.
> 
> SOUND :
> Unfortunately the weather turned suddenly today, below freezing and a chill wind then
> blankets of snow.
> So not much listening today, maybe eight tracks
> The stereo separation is MUCH better, probably because these reach into the 4k range
> smoothly.
> These easily keep up with the rest of my equipment now, it's nice to hear loud and clear
> and sterephonic music ! ( sometimes scaring the crap outta me with left & right info ).
> The sound is now " effortless ", and open, nice & tight too.
> 
> No time to play with EQ today or anything else, but so far i like what i hear.
> This is a big step up from the rockfords.
> 
> I hope that they loosen up, right now they are hardly moving and this is on approx
> 150 watts. Again, they have only played for about half an hour.
> 
> Thankyou Eric !
> You were very patient with me and took the time to accommodate me.
> Service like this is always remembered and valued.
> 
> I'll post again with an update once these loosen up and have played for a few days.


Thank you for sharing, you are very welcome glad to be of serv ice.


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## oabeieo

DeLander said:


> I got a PM from Eric checking on these in my truck. It occurred to me that I hadn’t posted any updates in a while. It’s not scientific or anything, but here ya go.
> In comparison to the Beymas that they replaced, the MB-8s are definitely more detailed and “open” sounding. They aren’t as warm or heavy sounding as the Beymas. They have a more punc
> hy kick type of sound, than a booming bass sound. This doesn’t mean the Beymas were boomy, just thicker sounding I guess.
> Again, remember, these 2 sets of drivers have identical installs, low and forward in my front doors. I’d really like to see how the MB-8s do in either sealed or ported enclosures.


Glad to see it all worked out.


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## DeLander

Yeah. Thanks Andy. Have you gotten yours yet ?
I still need to take system measurements if I can figure out how?


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## DeLander

Thanks to mikey7182 for enclosure info and several members who have provided info in my fiberglass thread, I’m almost convinced to build ported door enclosures for these. 
From Eric’s original thread, I gather that a .5 ft^ net enclosure, tuned to 60Hz is recommended for these. That tuning seems awfully low to me. Is it accurate ?


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## Eric Stevens

DeLander said:


> Thanks to mikey7182 for enclosure info and several members who have provided info in my fiberglass thread, I’m almost convinced to build ported door enclosures for these.
> From Eric’s original thread, I gather that a .5 ft^ net enclosure, tuned to 60Hz is recommended for these. That tuning seems awfully low to me. Is it accurate ?


60 Hz would too low. I suggest 65 to 70 Hz at .45 net


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## DeLander

Eric Stevens said:


> 60 Hz would too low. I suggest 65 to 70 Hz at .45 net


Cool. Thanks Eric. What is the volume of the driver displacement inside the box ?


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## PsyCLown

Bit of a thread necro, but how are your enclosures coming along?

I assume ported for a bit more bass? Sealed and some EQ should be decent as well though?


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## DeLander

PsyCLown said:


> Bit of a thread necro, but how are your enclosures coming along?
> 
> I assume ported for a bit more bass? Sealed and some EQ should be decent as well though?


Enclosure plans were put on hold due to Winter and lack of ? for fiberglass materials. I figured the materials would be between $200-$250 for everything I would need. ☹


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## nyquistrate

DeLander said:


> Enclosure plans were put on hold due to Winter and lack of ? for fiberglass materials. I figured the materials would be between $200-$250 for everything I would need. ☹


Checking to see if you built those ported boxes for the doors?


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## DeLander

nyquistrate said:


> Checking to see if you built those ported boxes for the doors?


Nope. Once it warmed up, I had subwoofer issues. Ended up taking the Alpine SWS-15 out and upgrading to a Pro Audio driver for a change. Super glad I did too.


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## nyquistrate

DeLander said:


> Nope. Once it warmed up, I had subwoofer issues. Ended up taking the Alpine SWS-15 out and upgrading to a Pro Audio driver for a change. Super glad I did too.


Is that swap on here somewhere?


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## DeLander

Here it is. Sorry, some of the pics turned sideways when I posted them. 
https://www.diymobileaudio.com/forum/build-logs-project-install-gallery/401217-pa460-vbss.html


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## DeLander

I guess it’s time for another little update on this. The MB-8s used as midbasses from 80-400Hz or so are awesome !!!
They definitely blend in well with the new high output sub. 
The system sounded really good before, but the new sub has really taken it to another level ?. I’ve never really listened to EDM,Trance, club type music much. Always been a pretty much Rock guy. But, DAMN, this electronic music just sounds awesome now so I’m starting to get into listening to more of it. 
I still don’t have a stand alone DSP, but tuning with just the 880PRS and my ears sounds the best by far of any system I ever had. 
Now I know why guys run Pro Audio drivers in their setups. They’re just so clean and dynamic sounding. Fantastic!!


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## dcfis

Agree going back to jbl gti 1500. As good as the ae sub is it still sounds like a clean sub not a dynamic, punchy resonator. The ae is louder with more x max so this time I'm going with 2



DeLander said:


> I guess it’s time for another little update on this. The MB-8s used as midbasses from 80-400Hz or so are awesome !!!
> They definitely blend in well with the new high output sub.
> The system sounded really good before, but the new sub has really taken it to another level ?. I’ve never really listened to EDM,Trance, club type music much. Always been a pretty much Rock guy. But, DAMN, this electronic music just sounds awesome now so I’m starting to get into listening to more of it.
> I still don’t have a stand alone DSP, but tuning with just the 880PRS and my ears sounds the best by far of any system I ever had.
> Now I know why guys run Pro Audio drivers in their setups. They’re just so clean and dynamic sounding. Fantastic!!


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## POLKAT

FYI, the MB-8 just barely fits inside of a current-gen Mazda 6 front door. I made a 2.25" spacer to replace the stock mount. 

Here is video proof. I kept the MB-8 wrapped in its plastic to keep it from getting damaged just in case it was too deep.

For some reason I can't get embedded Youtube videos to link properly so here is a direct link instead...

https://youtu.be/f2Ei0USKKKY


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## dcfis

That's awesome!


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## rton20s

POLKAT said:


> FYI, the MB-8 just barely fits inside of a current-gen Mazda 6 front door. I made a 2.25" spacer to replace the stock mount.
> 
> Here is video proof. I kept the MB-8 wrapped in its plastic to keep it from getting damaged just in case it was too deep.
> 
> For some reason I can't get embedded Youtube videos to link properly so here is a direct link instead...
> 
> https://youtu.be/f2Ei0USKKKY


Whoa! That is CLOSE. I thought for sure the door stop would require the use of the Neo version. This is great news.


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## EvAnA

Just another "it fits" post.

Pics of my adapter for 2015 F150, was pleasantly surprised I got clearance on the first try with just a 3/4" mount.

I now have real midbass oooomph and all the wonderful new vibration noises to chase down in my door panels.


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## Eric Stevens

EvAnA said:


> Just another "it fits" post.
> 
> Pics of my adapter for 2015 F150, was pleasantly surprised I got clearance on the first try with just a 3/4" mount.
> 
> I now have real midbass oooomph and all the wonderful new vibration noises to chase down in my door panels.



If you havent already For best results make sure to seal the front side of the MB8 to the grill opening using fast rings or other foam.

Have fun with some butyl based dampening material on the plastic door skin.


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## EvAnA

Eric Stevens said:


> If you havent already For best results make sure to seal the front side of the MB8 to the grill opening using fast rings or other foam.
> 
> Have fun with some butyl based dampening material on the plastic door skin.


I've got closed cell foam strips to surround the driver and already started with more second skin on the inner door panel. :thumbsup:


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## minbari

Calking Rope works wonders for areas that you cant get cld into. it works really well if you get vibrations from where window and door lock controls mount on the panels. alot of the time they just push fit into the panel and vibrate like crazy


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