# Unpleasant HLCD sound



## ehiunno (Feb 26, 2008)

I just spent a long time tuning the horns in my latest build with an RTA, and they sound terrible. The sound is just strange. Its far from honky, loud, or in your face. It just sounds really unclear, muddy and almost distorted, even though my RTA shows low THD. The strange thing is, they aren't that loud. At all. I had to turn down my midbass and subs to match them. The total system volume can get pretty loud, but its certainly not because the horns are tearing my head off.

With tuning, they play more or less flat. I stuffed the horn with polyfil and used 1" PVC pipe on the top and sides to round the transition into the dash because its difficult to get them far back in my car. This certainly all made it sound better, but still pretty bad. My crossover is set at 1300 hz @ 24 dB/octave.


Anways, can anyone think of a reason this might happen? I'm worried the compression drivers or the amp might be damaged. Sometime soon I'll try switching in another amp to see if that helps. Maybe I didn't tighten the screws down enough on the drivers when bolting them on the horn, but that seems ridiculous. Let me know if you have any ideas!

EDIT: Forgot to mention I am using mini bodies with CD1 pro drivers, B&C 6NDL44 midbasses (awesome) and ED 8s (decently awesome)


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## Mic10is (Aug 20, 2007)

take out the polyfill and the ID horns dont need all the additional stuff if they can be made to transition with the under dash. 

Where in VA are you?


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## ehiunno (Feb 26, 2008)

I'm in Hampton, Va. I tried it without the polyfil. Trust me, the polyfil helps. I'll play with taking it out tomorrow though. The PVC actually makes the dash transition, because they are so far forward the transition is really rough. The hood release causes the drivers side horn to have a gap between the horn and the dash for most of the way, so the passenger side has a large gap the entire way across. The PVC is used to bridge the gap and smooth the transition. I'll try to take some pictures tomorrow.


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## Mic10is (Aug 20, 2007)

processing and amps?


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## ehiunno (Feb 26, 2008)

Source and processing is a CarPC. The subs and the midbasses sound good, so I'm fairly sure its not the PC. The amp on the horns is a bridged old Eclipse 3640. I'll try swapping that out for another as soon as I can. FWIW, the midbasses have a bridged Zuki eleets 4 channel (original line) and the subs have a bridged Boston GT22.

My second thought was that I might just not like the sound of horns. This is the first set I've heard, but I figure there is no way anyone would ever have competed in the IASCA with a top end that sounds even close to this bad. Its got to be possible to get them to sound good.


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## Mic10is (Aug 20, 2007)

horns playing by themselves donot sound great at all. but you seem to have a different problem.
what does the RTA look like?
whats the power ratio , horns:mid:midbass:subs?


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## monkeyboy (Jun 12, 2007)

Why did you bridge an amp to the horns? Mine are only running off of 25 Watts Per channel and I had to run the gains all the way down, and cut them back at the eq so they wouldn't overpower the mids running at 250 WPC.


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## ehiunno (Feb 26, 2008)

The power ratio is something like 250:200:100 per speaker. Honestly i have no idea how much power the Zuki makes bridged into 8 ohms and neither does anyone else, haha!

I only bridged the amp to the horns because I had the 4 channel Eclipse lying around and I figured there is no such thing as too much headroom, especially if I end up switching the horns out in the future. It really doesn't matter.

I'm going to go play with it in a little bit. I'll come back with an RTA screen shot if I can't get it to sound better.


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## subwoofery (Nov 9, 2008)

Play with your level first before doing anything else. It really does help balance out the system and let you use less EQ. 
Also: 
http://www.diymobileaudio.com/forum/hlcd/105354-eric-stevens-horn-tune.html
http://www.diymobileaudio.com/forum/hlcd/97498-tuning-your-hlcd-system.html 

Hope that helps, 
Kelvin


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## Eric Stevens (Dec 29, 2007)

I would say you have a problem with the compression drivers themselves.

First thing to check would be the voice coil gap. Use masking tape folded so it has two sticky sides out and drag it through the gap to clean it.

Next carefully check the diaphragm to make sure the voice col is glued to the dome all the way around. Do this by gently tugging on the voice coil using your fingers.

Testing the compression drivers is done easily with a tone generator, sweep with a sine wave and it should sound clear and undistorted at all frequencies in its usable frequency range.

Eric


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## ehiunno (Feb 26, 2008)

First of all, I just want to say thanks to everyone for all of the help and ideas.

Tuning this system is turning out to be considerably more difficult than the other one's I have had in the past, but I think I'm making progress.

I did a few things that improved the sound dramatically. First, I played with the amount of stuffing to see if that helped. Removing some of it helped them sound less muddy, but taking it all out they became offensive and in-your-face. It still sounded pretty bad either way. The next thing I did was switch the phase on one of the mids and re-eq'd them. This seems to have helped a lot. It centered the stage and allowed the horns to come through the mix a lot more. I guess I still have a lot to learn!

It still doesn't sound awesome, but I'm taking a break for now. Now that I have the levels better I'm going to eq the horns a little more later.

Eric, thanks for the tip. I'll do a sine sweep and see if it sounds distorted before I go taking the drivers out. I'm thinking more now that I just got overzealous with the pink noise without listening to enough tracks.


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## ehiunno (Feb 26, 2008)

I spent a good bit longer with it. I have it sounding decent, but not even close to what I was hoping for. Now my biggest problem is that I can't get the 100-600Hz region to sound the same from both seats. When both are more or less RTA flat individually, the drivers seat has a ton of resonances that aren't present in the passenger side and vice versa.

I should probably flip the midbasses back into phase and give it another try, but at this point I'm out of motivation. Thanks for all the help guys, I do appreciate it.


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## veritasz34 (Jul 25, 2011)

Horns are tough and not easy to get right in every car.The mini horns to me are tougher to work with than the full size horns when it comes to tuneing. Some actual pics of the horns mounting and transition to the dash would also be helpful..


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## minbari (Mar 3, 2011)

I had alot of the same problems you are having and I found it simply output power. I am just running deck power of an alpine right now, but I have the horns turned down almost all the way. I am guessing that the xs65s are getting about 35 watts and the horns are getting about 5-7 watts. If I turn up the horns anymore it is shrill and amazingly bright. set the way it is now it mixes and images REALLY well. (although i will admit I could use an EQ to fix all the problems. Once I get my amplifiers and EQ installed I am sure it will work better)

one way to look at this, from a power stand point is efficiency. the horns are about 108dB efficient and most 6.5" mid-bass are about 90dB (mine being 92dB) that is almost 20X more efficient! so if you are powering your horns with 25 watts and you mid-bass are getting 250Watts you will still have to pad down those horns!


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## ehiunno (Feb 26, 2008)

Thanks for the added replies. I did actually get it to sound pretty good, and I'm more or less satisfied with it the way it is now 

I understand what you're saying minbari, but that is kind of the opposite of the problem I had. For me it was that I was having to turn the horns down relative to the midbass, and I verified via RTA that I wasn't just hearing things. Right now I have it set so that the horns have only slightly less gain than the midbasses. They get plenty loud though, believe me.


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## minbari (Mar 3, 2011)

oh I know. even on the alpine deck power, it gets soo loud I cant stand it, lol. cant wait until i put "real" amplifiers in there


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## Ayanna (Aug 12, 2011)

Mic10is said:


> horns playing by themselves donot sound great at all. but you seem to have a different problem.
> what does the RTA look like?
> whats the power ratio , horns:mid:midbass:subs?


having stranging noice while playing horns and its very i cant explain those voice i checked it when i sepertly play its fine but when i fit in its noising.....


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## Horsemanwill (Jun 1, 2008)

Ayanna said:


> having stranging noice while playing horns and its very i cant explain those voice i checked it when i sepertly play its fine but when i fit in its noising.....


wat?


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## veritasz34 (Jul 25, 2011)

Sounds like you have an enviroment resonance problem..something in the car is resonateing when you have both on. When played singular you may not have enough energy for it ti induce noise but when together it resonates..This may be a pain to track down if it is the problem..


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