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View Full Version : Confused: set gains w/Sub setting at "0" or "+15"?



Weeznur32
06-05-2012, 05:12 AM
I have heard many people say to set gains with DMM with the sub setting on headunit at "0".

Have also heard people say to set it to "+15" before setting gains.

Which is the proper way to do it?

Imtjnotu
06-05-2012, 05:16 AM
I was. Always told to get the full pre volt output to set it to the highest

---------- Post added at 01:16 AM ---------- Previous post was at 01:15 AM ----------

keep_hope_alive

Mitch86
06-05-2012, 05:18 AM
From what I understand it depends on the HU you're using. Some headunit the "sub level" simply increases the pre-out voltage. So maxing it out gives you the max voltage your headunit is rated for. My suuggestion is to try to set the gains with it at 0 and if you get an extremely low reading even with the gains maxed, you need to turn up the sub setting. Now that's what I understand of it. I have never had that problem myself.

keep_hope_alive
06-05-2012, 02:17 PM
Alpine head units - sub level is attenuation only. set gains at preferred listening level. i like shooting for sub level 6-8 for gains. then you can increase or decrease based on the recording or personal tastes.

i usually adjust sub level with each album.

Boomsday
06-05-2012, 02:24 PM
Alpine head units - sub level is attenuation only. set gains at preferred listening level. i like shooting for sub level 6-8 for gains. then you can increase or decrease based on the recording or personal tastes.

i usually adjust sub level with each album.

Is this just on alpine units, or have you heard of any others that are like this??

I always set my 9887 to +15 then set the gains accordingly..

40oz
06-05-2012, 02:49 PM
My Kenwood has sub level that goes from -15 to +15. I set my gains with it at 0, with no problems. I only use the sub level to turn down the bass, never turn it up.

keep_hope_alive
06-05-2012, 02:52 PM
it's relative. review the owner's manual for your specific hu's function.

in general, get some output then give yourself headroom.

av83
06-05-2012, 02:52 PM
Alpine head units - sub level is attenuation only. set gains at preferred listening level. i like shooting for sub level 6-8 for gains. then you can increase or decrease based on the recording or personal tastes.

i usually adjust sub level with each album.

I'd like to know about the sub level on the excelon models. I set my amp with it at +15db to try and get the best possible voltage out of the rca's.... Am I wrong?

40oz
06-05-2012, 03:15 PM
I'd like to know about the sub level on the excelon models. I set my amp with it at +15db to try and get the best possible voltage out of the rca's.... Am I wrong?

Isn't there a possibility of a clipped signal or at least distorted if you turn the sub level all the way to +15 to set your gains? Isn't it sort of the same thing as setting your gains with the head unit volume on max?

av83
06-05-2012, 03:16 PM
Isn't there a possibility of a clipped signal or at least distorted if you turn the sub level all the way to +15 to set your gains? Isn't it sort of the same thing as setting your gains with the head unit volume on max?

That's what I'm trying to find out.

40oz
06-05-2012, 03:42 PM
That's what I'm trying to find out.

I would just compromise and set the gains with the sub level at +10, that way you can still get higher voltage and eliminate any possibility of distortion/clipping. I might do it this way once I switch up my system and have to reset my gains.

av83
06-05-2012, 03:46 PM
I would just compromise and set the gains with the sub level at +10, that way you can still get higher voltage and eliminate any possibility of distortion/clipping. I might do it this way once I switch up my system and have to reset my gains.

I've been thinking about doing exactly that.

whitedragon551
06-05-2012, 03:49 PM
You folks are confusing bass level with attenuation. Some headunits have a bass attenuation setting that allows you to alter preout voltages. All headunits have a bass level. Alpines for example have the attenuation setting. That should be set at 15 to get the max preout voltage from the headunit. The bass level hower is different and should be set at 0. Altering the attenuation setting does nothing to introduce clipping, altering the bass level does.

Weeznur32
06-05-2012, 03:53 PM
exactly what i was looking for. Thank you

keep_hope_alive
06-05-2012, 07:32 PM
You folks are confusing bass level with attenuation. Some headunits have a bass attenuation setting that allows you to alter preout voltages. All headunits have a bass level. Alpines for example have the attenuation setting. That should be set at 15 to get the max preout voltage from the headunit. The bass level hower is different and should be set at 0. Altering the attenuation setting does nothing to introduce clipping, altering the bass level does.

agreed. the head unit manual should say if the adjustment is an EQ boost and it should tell at what frequency the boost is at.

Alpine has a bass level and a subwoofer level. bass level is an EQ (at 100Hz typically, unless parametric "bass engine pro"). subwoofer level is signal strength on that preout. this should be universal terminology but some companies do strange things. it is important to know what your HU is actually doing.

bgowdy31
06-05-2012, 09:02 PM
see this HU pre out stufff confuses me. i have a pioneer and i kno mine pre outs are like 2.5 if im not mistakin. which i think is pretty low compared to other HU

40oz
06-06-2012, 10:04 PM
agreed. the head unit manual should say if the adjustment is an EQ boost and it should tell at what frequency the boost is at.

Alpine has a bass level and a subwoofer level. bass level is an EQ (at 100Hz typically, unless parametric "bass engine pro"). subwoofer level is signal strength on that preout. this should be universal terminology but some companies do strange things. it is important to know what your HU is actually doing.


My head unit (Kenwood KIV-701) manual doesn't specify what the "Subwoofer Level" does exactly. Is it safe to assume that it is an EQ boost rather than adjusting the signal strength, since it is a Kenwood and doesn't have a separate "Bass Level" adjustment?

keep_hope_alive
06-06-2012, 10:08 PM
My head unit (Kenwood KIV-701) manual doesn't specify what the "Subwoofer Level" does exactly. Is it safe to assume that it is an EQ boost rather than adjusting the signal strength, since it is a Kenwood and doesn't have a separate "Bass Level" adjustment?

6ch/4V Preamp Outputs: The KIV-701 features front, rear and subwoofer 4-volt preamp outputs. The front and rear speaker preamp outputs are balance and fade adjustable. The subwoofer preamp output is non-fading. The front, rear, and subwoofer preamp outputs are fixed to the rear chassis of the head unit. The subwoofer preamp output features an independent level control (-15 to +15).

I'd have to guess that you won't achieve a 4V output without the level on +15. hard to say without a 0dB track an a scope.

It has a separate 5-band EQ so it's not a bass level. bass level is EQ.

keep_hope_alive
06-06-2012, 10:13 PM
see this HU pre out stufff confuses me. i have a pioneer and i kno mine pre outs are like 2.5 if im not mistakin. which i think is pretty low compared to other HU

It just means you need more amplifier gain than someone who has a 4V head unit. the same power can be achieved from most amps.

now, if you get an amp that can only make rated power with a max voltage input, -0dB source recording, gain at max, and supply voltage of 15+VDC, then you'll never get rated power. but that's how cheap amps are rated. any decent amp will do just fine with 2V or less.

The real concern with lower HU preout voltage is noise. the higher your amp gain is, the more noise you will have.

bgowdy31
06-06-2012, 10:32 PM
It just means you need more amplifier gain than someone who has a 4V head unit. the same power can be achieved from most amps.

now, if you get an amp that can only make rated power with a max voltage input, -0dB source recording, gain at max, and supply voltage of 15+VDC, then you'll never get rated power. but that's how cheap amps are rated. any decent amp will do just fine with 2V or less.

The real concern with lower HU preout voltage is noise. the higher your amp gain is, the more noise you will have.



ok with that said do you know anything about the soundstream dtr1.3400's

40oz
06-06-2012, 10:46 PM
6ch/4V Preamp Outputs: The KIV-701 features front, rear and subwoofer 4-volt preamp outputs. The front and rear speaker preamp outputs are balance and fade adjustable. The subwoofer preamp output is non-fading. The front, rear, and subwoofer preamp outputs are fixed to the rear chassis of the head unit. The subwoofer preamp output features an independent level control (-15 to +15).

I'd have to guess that you won't achieve a 4V output without the level on +15. hard to say without a 0dB track an a scope.

It has a separate 5-band EQ so it's not a bass level. bass level is EQ.

Nice, thanks. I forgot Crutchfield had such a detailed review.

So since it is a level adjustment, I can safely put it at +15 without worrying about clipping? Or should I stay safe and set it with it at +10?

40oz
06-07-2012, 01:56 PM
Well I emailed Kenwood and this was their response:

"I understand you are inquiring about the SUBWOOFER LEVEL on your KIV-701. This is an equalizer setting for the frequency and does not affect the output voltage. "

keep_hope_alive
06-08-2012, 12:48 AM
then ask them what frequency it boosts and what the Q is of the filter. if it is an EQ then they have to tell you those two things.

that response sounds like an Indian wrote it.

av83
06-08-2012, 12:52 AM
that response sounds like an Indian wrote it.

I agree.

av83
06-08-2012, 12:56 AM
I wasn't all that satisfied by the answer a guy at a local kenwood dealer/install shop told me over the phone. But he did say that the headunit will not send a clipped signal to the amp via sub rca due to the subwoofer level being on +15. That was in regards to my x994.