4ch bridged to 2ch - will imaging suffer?

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sunshinefc3s
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4ch bridged to 2ch - will imaging suffer?

Post by sunshinefc3s »

Guys,
I realize this may be a silly question, but I'm struggling to think this through and need some help...

I have a old Ti500.4 and want to bridge it to run my Elite65.cs front stage (deleting my rears). I also have an Alpine Imprint processor running my system. Now, if I bridge the amp, I know I lose "stereo" mode. However, what does bridging do for my imaging as far as the Imprint is concerned. If I re-tune the Imprint how will my image be affected?

Am I correct that Ti500.4 bridges by connecting the front L+/R- and rear L+/R-? How does amp know that the fronts are now R and the rears are now L.

Thanks.
-a
vwdude
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by vwdude »

Imaging won't suffer. The amps doesn't "know" left from right, front from rear. It has 4 channels at x watts, now it will have 2 channels at approximately twice the power.

You just need to make sure your signal goes to the proper inputs. I'm not familiar with that amp, some will accept signal on one of the two bridged channels and others require a Y splitter to run signal to both input channels that are bridged.

Your THD may suffer though from bridging. This generally is not an audible amount though, especially on an amp as good as the one you are using.
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sunshinefc3s
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by sunshinefc3s »

vwdude wrote:Imaging won't suffer. The amps doesn't "know" left from right, front from rear. It has 4 channels at x watts, now it will have 2 channels at approximately twice the power.

You just need to make sure your signal goes to the proper inputs. I'm not familiar with that amp, some will accept signal on one of the two bridged channels and others require a Y splitter to run signal to both input channels that are bridged.

Your THD may suffer though from bridging. This generally is not an audible amount though, especially on an amp as good as the one you are using.
Thanks. So, I need to disconnect the RCA cable from the Imprint rear output/rear amp input. Then I need to figure out which RCA inputs on the amp need to see the front L/R signal from the Imprint. Run the tune, and hope the increase in THD is imperceptible.

Anyone know about the RCA inputs on the Ti? I've heard that Ti amps like all RCAs to be connected.

Thanks.
-a
ttocs
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by ttocs »

pretty sure they have a switch on them that allows 2 channels to sample off of the other 2 so you only need one set of rca's to it but its been a while.
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ajaye
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by ajaye »

sunshinefc3s wrote:
vwdude wrote:Imaging won't suffer. The amps doesn't "know" left from right, front from rear. It has 4 channels at x watts, now it will have 2 channels at approximately twice the power.

You just need to make sure your signal goes to the proper inputs. I'm not familiar with that amp, some will accept signal on one of the two bridged channels and others require a Y splitter to run signal to both input channels that are bridged.

Your THD may suffer though from bridging. This generally is not an audible amount though, especially on an amp as good as the one you are using.
Thanks. So, I need to disconnect the RCA cable from the Imprint rear output/rear amp input. Then I need to figure out which RCA inputs on the amp need to see the front L/R signal from the Imprint. Run the tune, and hope the increase in THD is imperceptible.

Anyone know about the RCA inputs on the Ti? I've heard that Ti amps like all RCAs to be connected.

Thanks.
-a
OK TRY THIS AT YOUR OWN RISK. I know some old RF 4 channel amps are kind of set up to run this way to achieve a stereo bridge using only one set of RCA inputs. Maybe someone can confirm if this will work on this amp, I have no idea.

This is assuming the Imprint/HU will be handling your xover settings as well. Feed the Imprint front L+R outputs to the Ti front L+R inputs as normal. Set the CONFIG switch for both front and rear channels to BY as well as for the AUX outputs. Set the input select switch to F, so your AUX Output will have the same signal as the Front Input is receiving. Use a tiny RCA (ie make one) and loop the Aux Outputs back into the Rear Inputs BUT REVERSE THEM. From there to achieve stereo, wire the front L+ and the rear R- speaker outputs to one channel/side, and the rear L+ and the front R- to the other side/channel. It may work. It may also cause a tear in the space-time continuum ending life as we know it.

Or you could just buy two of these
http://www.monoprice.com/Product?ab3=b& ... id%3D10218

It will cost you a whopping dollar and change, then feed both front L and R with the Imprint's Right output signal, feed both rear L and R with the Imprint's Left output signal, then bridge your front channels as normal for your right speaker, bridge your rear for your left speaker. This way you feed all 4 inputs and still achieve stereo, which is worth it. I had my fronts running off a bridged 4 channel mono, figured out it could do it stereo without feeding the rear RCA inputs and changed it, so glad I did.
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Drock
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by Drock »

Alternatively, I would find yourself a nice ti600.2 and call it a day. Lol



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sunshinefc3s
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by sunshinefc3s »

Drock wrote:Alternatively, I would find yourself a nice ti600.2 and call it a day. Lol
Ha, already gt one. Its running my sub!

I bridged the channels today, but didn't run a tune on the Imprint. I got sound only from one speaker. The explanation could just be that the magical black box of mystery needs to be reset. Will do a bit of troubleshooting this w/e.
-a
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by Kirghiz »

Drock wrote:Alternatively, I would find yourself a nice ti600.2 and call it a day. Lol
I always thought the two channel amps were more versatile than 4 channel for this reason.
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Drock
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by Drock »

If you google it there are diagrames how to bridge an amp stereo.


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ajaye
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by ajaye »

Drock wrote:If you google it there are diagrames how to bridge an amp stereo.


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I think his issue is more how to do it with only one set of inputs to the amp. Normally I would say just use both front and rear outs since he's not using them with no rear fill anyway, so both left outs to front L and R ins, both rights to rear L and R ins, then front channels bridged become left channel and rear channels bridged become right channel...but if Imprint works the way I imagine it does (mic in listening position(s) to pick up series of test tones through each speaker), it will be a mess that way. Splitting the front outs from the imprint instead and treating front amp ins as left and rear amp ins as right solves that issue though for next to nothing cost-wise.

Going with 2 summed (mono) channels instead of stereo left and right kind of defeats having a lot of the features of Imprint to me. I would ditch it and just use all 4 channels, high pass the fronts to the tweeters and band pass the rears to the mid woofers before doing 2 mono channels with Imprint.
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by ttocs »

what is the confusion with this? Is there a reason we are trying to use only 2 inputs on the amp?
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by sunshinefc3s »

ttocs wrote:what is the confusion with this? Is there a reason we are trying to use only 2 inputs on the amp?
We are trying to figure out if we can retain imaging when bridging a 4ch to run front stage with the help of a processor. If bridging the amp only results in two mono outputs, then the purpose of the processor/imaging is defeated.
-a
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by ttocs »

two mono ouputs? In my world two mono outputs can be the same as a stereo signal.
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by sunshinefc3s »

ttocs wrote:two mono ouputs? In my world two mono outputs can be the same as a stereo signal.
That's great, if that's the answer. Now, how do I make that happen with an Ti500.4? At the moment, the 500.4 is bridged (front L+/R-, and rear L+/R-), and the inputs are in the front L and R. This is not outputting properly....but I have not had time to mess with it yet. I will tomorrow.
-a
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by Eric D »

Why is this so hard?

Image
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by ttocs »

or even just feed the rear rca's into the amp I mean the front/rear channels are the same on the left and the right but yea a simpe Y-adaptor would work as well. This really isn't difficult and unless something is messed up the only thing you should notice is probably a little more headroom with the extra power.
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by vwdude »

sunshinefc3s wrote:
ttocs wrote:two mono ouputs? In my world two mono outputs can be the same as a stereo signal.
That's great, if that's the answer. Now, how do I make that happen with an Ti500.4? At the moment, the 500.4 is bridged (front L+/R-, and rear L+/R-), and the inputs are in the front L and R. This is not outputting properly....but I have not had time to mess with it yet. I will tomorrow.
-a
There's no IF. The definition of stereo: two mono channels that can play independent of each other. The key there is 2. Mono is 1 channel of audio, stereo is 2 channels of audio. 5.1 is 6 channels of audio. It's really not that hard. You have 1 left and 1 right.

The only question is do you need y splitters to connect your signal to the amp or can it accept one signal per channel. I will look it up in the manual and report back.

Edit: the 500.4 manual posted on here doesn't cover this scenario but the manual for the zx475ti does. Here is a screenshot of what it says...now how similar are the amps? I would think that they are very similar, but don't hold me accountable.

Image
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by vwdude »

So according to this diagram, if you bridge the front together and the rear together you can run left and right signal to just the front. This means no need for y splitters.

Your situation is slightly different from this example where you will be running high pass not lowpass. Then your aux out will be lowpass.
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by ttocs »

I think with the imprint piece, depending on which deck you have, you could run the amp in 4 channel mode and use the electronic cross overs in the deck to control the signal to them - since your not using the rear speaker. I know my deck has the option but not sure which other do.
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by kg1961 »

Eric D wrote:Why is this so hard?

Image

x2 should be easy unless the unit is damaged or the pots are acting up
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by Eric D »

The diagram in the ZX475ti manual is for mono operation, not stereo. The only way to get 2-channel stereo out of a ZX450, ZX475ti, or Ti500.4 is to use "Y" cables unfortunately.
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by vwdude »

Eric D wrote:The diagram in the ZX475ti manual is for mono operation, not stereo. The only way to get 2-channel stereo out of a ZX450, ZX475ti, or Ti500.4 is to use "Y" cables unfortunately.
Oh, I didn't think about that.
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by trickyricky »

vwdude wrote:
Eric D wrote:The diagram in the ZX475ti manual is for mono operation, not stereo. The only way to get 2-channel stereo out of a ZX450, ZX475ti, or Ti500.4 is to use "Y" cables unfortunately.
Oh, I didn't think about that.

Yep, when you only use the front inputs and then bridge the channels you'll get two mono channels.So you need y adapters.
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by sunshinefc3s »

trickyricky wrote:
Yep, when you only use the front inputs and then bridge the channels you'll get two mono channels.So you need y adapters.
Guys, thank you very much for the info. This is my first foray into bridging anything non-sub. The Imprint is an Alpine H660 (not an HU), but that should not mater, operation should be the same on the output side of the box. I will try tomorrow and report back. Much appreciated.
-a
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Re: 4ch bridged to 2ch - will imaging suffer?

Post by dbjury »

Have you considered running front speakers active. Tweeters off front channels. Woofers off rear channels. Using you imprint crossovers.


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