# Horn to midbass power ratio



## nubz69 (Aug 27, 2005)

I have recently been working on the tuning of my car little by little and I am starting to get close but a few little things have been off. One of the bigger problems I have just recognized is that as I increase my volume level on my HU the horns and the midbasses increase in volume at different rates. Currently they are being powered by a Soundstream Picasso. I know there is a recommended ratio of power amps for horns, mids and subs but I don't think my issue is due to this. Or is it? For the first time I am not quite sure how to tackle a problem. The obvious answer is that I need the gain to increase in different ratios for each set of channels but I don't know of a way to do that. So what do I do here?


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## minbari (Mar 3, 2011)

so do you have the midbass and the horn on the same channel or is this a 4ch?


in general you want a very high sensitivity midbass. what kind of midbass are you using?

to give you an example (from my own setup) if yo uare running the ID x65 which is 92dB 1W/1m with the cd1e which is 108dB 1W/1m that is 16 dB difference. that is 40X more sensitive. So, if your horns have 10 watts of power, your midbass would need 400 watts.

most horns are 8 ohm, so they get 1/2 the wattage as the 4ohm rating of the amplifier. but you will still need to run the gain all the way down on the horn channels and turned up some amount on the midbass channels.


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## nubz69 (Aug 27, 2005)

minbari I guess I should have put more info about my system.

Here is my setup - sony DSX-S310BTX --> Bitone --> 4 channel SS Picasso --> 2 channels going to DE500 + ID bodies + 2 Channels going to Sony GTR midbasses.

My midbasses are rated at - Sensitivity (db) : 86 +/- 2 dB/1W/1m from what I can find

I know that is not a good match in efficiency (my compression drivers are ~ 107db/w/m) but that is what I am using.

So the question is how can I make this work as good as possible as I will be using these drivers for a while. The gains are set properly for an average listening level but if I drop the volume the gains don't stay matched. Here is one way to think of it.


Volume set @ 10
Tweeter:50db
Woofer:45db

Volume set @ 20
Tweeter:70db
Woofer:70db


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## Mic10is (Aug 20, 2007)

1:3:5
Horns:mid:subs


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## minbari (Mar 3, 2011)

nubz69 said:


> My midbasses are rated at - Sensitivity (db) : 86 +/- 2 dB/1W/1m from what I can find
> 
> I know that is not a good match in efficiency (my compression drivers are ~ 107db/w/m) but that is what I am using.
> 
> ...


nothing will fix what you are seeing. those are simply not sensitive enough to run with horns. they are 20dB less sensitive, that works out to 100X less. (I edited my last post as I did the math on it wrong) so for 10 watts going to the horns you need 1000 watts going to the 6.5! not realistic.

do you have the 4ch RCA wired independantly? if you do, try using the fader and move more signal to the midbass channels. this will give you more room to fiddle with the gains.

so you will have to make a compromise. do you listen to it more at 20 or more at 10? tune it for the setting you listen to and start saving for a better midbass.


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## thehatedguy (May 4, 2007)

Like Mic stated, that's what I try to roll with. 1:3 or 1:4 is where I try to get.


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## nubz69 (Aug 27, 2005)

Mic, thanks, that is what I was looking for.

The amp is 25w X 4 but the DE500 are 8 ohm so they are getting about 12.5w. So I am at a 1:2 ratio in wrms, if I built a voltage divider for the RCA's going to the horns I could increase that to 1:4, but shouldn't I be able to create the same effect with my gain settings? 

Here is some more info on the amp if you are not familiar with it. http://www.soundstream.com/manuals/AMP/REFERENCE/picasso2/picasso2.pdf

I understand the difference in DB is huge but there must be some way to compensate for this. The two ideas I have are to either build some sort of compensation circuit or I might just try to play with the sensitivity switches on the amp to see if I can get closer to ideal.

I think I may be able to bootstrap a solution using the bit one volume compensation feature but that seems like a lot of work compared to just using more efficient drivers. My original plan was to use some 2118s but they would require a whole lot more work then I want to put into this system.

Everything is active so I have a lot of flexibility, just not sure the best way to takle this without changing drivers. The thing is that even though my drivers are inefficient, your 92db drivers are also very inefficient when compared to your 108db drivers. I would think you and everyone else, should be having the same problem just on a much smaller scale with properly set gains.


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## thehatedguy (May 4, 2007)

It's 108 dB unequalized. That will drop some once it is equalized...but so will the other speakers.

You could do the L-pad on the RCAs, but making a voltage divider speaker level would/could have some benefits like lessing the impedance bumps of the driver and horn...which is a good thing.


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## BigRed (Aug 12, 2007)

Back in the day Eric from Image told me 1:3:5. horns:mids:subs

just saw Mic had already went there


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## Mic10is (Aug 20, 2007)

BigRed said:


> Back in the day Eric from Image told me 1:3:5. horns:mids:subs
> 
> just saw Mic had already went there


slowpoke!!


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## rawdawg (Apr 27, 2007)

Is the 1:3:5 ratio assuming equal speaker efficiencies across the board?


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## Eric Stevens (Dec 29, 2007)

rawdawg said:


> Is the 1:3:5 ratio assuming equal speaker efficiencies across the board?


No it is to compensate for the unequal efficiency.

Also the 5 on sub is based upon the average persons hidden needs to boom a little. So if your a purist equal power to mids and subs.

Eric


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## Eric Stevens (Dec 29, 2007)

nubz69 said:


> I have recently been working on the tuning of my car little by little and I am starting to get close but a few little things have been off. One of the bigger problems I have just recognized is that as I increase my volume level on my HU the horns and the midbasses increase in volume at different rates. Currently they are being powered by a Soundstream Picasso. I know there is a recommended ratio of power amps for horns, mids and subs but I don't think my issue is due to this. Or is it? For the first time I am not quite sure how to tackle a problem. The obvious answer is that I need the gain to increase in different ratios for each set of channels but I don't know of a way to do that. So what do I do here?


If you get the drivers level matched at one volume they should stay level matched within the output capabilities of that amp as long as all channels are within the linear operating range of the amp.

Sounds like you are running out of mids as you raise the volume and have possibly exceeded the amps output capability on those channels. So higher efficiency midbass and more power would be my suggestilon. 

Think about bridging the 4 channel to your midbass and add a small 2 channel to the horns.

Eric


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## Mic10is (Aug 20, 2007)

Eric Stevens said:


> No it is to compensate for the unequal efficiency.
> 
> Also the 5 on sub is based upon the average persons hidden needs to boom a little. So if your a purist equal power to mids and subs.
> 
> Eric


bc what person doesnt like a lil extra Boom when driving on a nice day!!


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## subwoofery (Nov 9, 2008)

nubz69 said:


> Mic, thanks, that is what I was looking for.
> 
> The amp is 25w X 4 but the DE500 are 8 ohm so they are getting about 12.5w. So I am at a 1:2 ratio in wrms, if I built a voltage divider for the RCA's going to the horns I could increase that to 1:4, but shouldn't I be able to create the same effect with my gain settings?
> Just leave the gains on your horns to the minimum... No need for a voltage divider... IMO
> ...


Easiest way to solve your problem is really to use more efficient drivers... 
Eric said it best, you might run out of mids unless your levels aren't set correctly... 

Kelvin


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## minbari (Mar 3, 2011)

subwoofery said:


> Easiest way to solve your problem is really to use more efficient drivers...
> Eric said it best, you might run out of mids unless your levels aren't set correctly...
> 
> 
> ...


X2 ^^^ this!

couldnt have said it better myself. yes they are not as efficient as the horns, but since this is the decibel system, which is logrithmic, they are leaps and bounds more efficient than 86.


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## Eric Stevens (Dec 29, 2007)

Another factor related to this is something that I have struggled to get people to understand for years.

Since the HLCD are so efficient and the power levels low relative to power handling limits the midbass will hit power compression far sooner than will the horns. In addition most 1" dome tweeters even those that can take 1000 watts dynamic will go into compression well before their midrange counterparts. So with someone who has gotten accustomed to the high end compressing at high volumes making the system less dynamic and forward than it would be otherwise think that the HLCD system is overly forward especially at higher volumes when what they are actually experiencing is a lack of compression. 

Eric


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## nubz69 (Aug 27, 2005)

minbari said:


> X2 ^^^ this!
> 
> couldnt have said it better myself. yes they are not as efficient as the horns, but since this is the decibel system, which is logrithmic, they are leaps and bounds more efficient than 86.


I would agree but there is one problem. The gains are balanced when I am at a normal listening level. When I drop the level to background music, the mids drop more then the horns. Which is the opposite of what you are describing.

I think I may have some gain set wrong somewhere, I am going to take some time and reset all my gains and see if that makes a difference. I wonder if the Bitone auto gain setup caused some issues as I also have a small hiss problem.


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## Eric Stevens (Dec 29, 2007)

nubz69 said:


> I would agree but there is one problem. The gains are balanced when I am at a normal listening level. When I drop the level to background music, the mids drop more then the horns. Which is the opposite of what you are describing.
> 
> I think I may have some gain set wrong somewhere, I am going to take some time and reset all my gains and see if that makes a difference. I wonder if the Bitone auto gain setup caused some issues as I also have a small hiss problem.



All levels should go up and down equally unless there is a problem. Is it possible to have varying gain with volume with the Bitone?

Eric


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## subwoofery (Nov 9, 2008)

nubz69 said:


> I would agree but there is one problem. The gains are balanced when I am at a normal listening level. When I drop the level to background music, the mids drop more then the horns. Which is the opposite of what you are describing.
> 
> I think I may have some gain set wrong somewhere, I am going to take some time and reset all my gains and see if that makes a difference. I wonder if the Bitone auto gain setup caused some issues as I also have a small hiss problem.


Do you have the same Xover as HP (horn) and LP (mid)? 
Say 1.25kHz? If yes, try to mute everything but 1 horn and play a 1.25kHz tone and listen for the loudness. Then mute that horn and play one mid (same side is better). Do the same for the other side. 
Then balance your sound so that both sides have the same level. 

Not the best way but should get you close to what you need... 

Again, leave the horns gain @ the amp to the minimum and just increase the mids gain. 

Kelvin


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## [email protected] (May 14, 2009)

Eric Stevens said:


> All levels should go up and down equally unless there is a problem. Is it possible to have varying gain with volume with the Bitone?
> 
> Eric


x2 on this. 

It is possible that you have the Dynamic Equalizer activated?



> Bit One Dynamic Equalizer.
> System automatically self-adjusts through an equalization between low and high listening levels that can be set by the user and controlled by the DRC



Regards Barney


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## nubz69 (Aug 27, 2005)

Eric Stevens said:


> All levels should go up and down equally unless there is a problem. Is it possible to have varying gain with volume with the Bitone?
> 
> Eric


Hence the post 

I haven't had time to look into this yet but I hope I will by this weekend.


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## Toastytoy (Jun 9, 2005)

one thing i never understood was the big deal with sensitivity when people talk about horns. If your horns are much more sensitive than the mids why can't you just throw 500 watts to the mids and 10 to the horns or something like that?


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## subwoofery (Nov 9, 2008)

Toastytoy said:


> one thing i never understood was the big deal with sensitivity when people talk about horns. If your horns are much more sensitive than the mids why can't you just throw 500 watts to the mids and 10 to the horns or something like that?


POWER COMpression!!!!! 

Kelvin


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