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Discussion Starter #1
I'm in the middle of an install using a Kenwood XR901-5, 5 channel amp. I intend to bridge the XR901-5 to power a set of midwoofers, and use the remaining channel for my sub. The amp signal is coming from 2 channels of an Alpine DSP. I only have 2 output channels from the Alpine available for this amp, so the XR901-5 cannot receive a 4 channel input, unless I use RCA splitters, which I'd rather not have to. Anyone know if this amp needs 4 channels of input to work in bridged mode, or can I just use inputs 1 and 2 on the amp? The manual was unclear on this.

Thanks
 

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I don’t have personal experience with that amp but judging from the manual it looks like you will be ok with just using line in (b) and flipping the input selector to (ab).
 

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It is my belief that both inputs (A + B) need signal to be able to bridge them. You would need splitters. SUB channel is generated off those inputs.

Although, you could just try and find out.

Sent from my SM-G975U using Tapatalk
 

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Then that could be a problem, becuz I assume the signal from the DSP intended for the midwoofers will be playing a different freq range than the subs should play.
If you are using a DSP and have both SUB out and Mid out of the DSP, that will work fine, just use the correct inputs. Mid output split to both A and B input of Amp, and Sub output to Sub input. Put switch in the Sub input mode.
 

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Discussion Starter #6
If you are using a DSP and have both SUB out and Mid out of the DSP, that will work fine, just use the correct inputs. Mid output split to both A and B input of Amp, and Sub output to Sub input. Put switch in the Sub input mode.
Ahh.. got it. My original post was actually incorrect- I have 2 output channels from the DSP AND a sub output from the DSP available, so this should work with splitters. Thanks!
 

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Discussion Starter #7
Just an update in case someone is Googling the Kenwood XR901-5. Kenwood technical support got back with me and confirmed that Mike-G was indeed correct. The amp requires 4 input channels, so splitters must be used.
 

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This is similar to something I had to do a few years ago.Running a RF Punch 4ch amp and wanted to bridge it for the front door woofers.I contacted RF tech support and guy told me that just feeding the amp 2 channels of input and setting the input switch to "2ch mode" would not work because the outputs would all be mono.So from the DSP I had to use Y-splitters feeding half the amp the left signal and the other half the right signal.Set input switch to "4ch mode" and this kept everything playing in stereo.

Some amps are designed to do this for people running subs only and have just 2 channels of input.The amp internally combines the signal and feeds the other 2 outputs.
 

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This is similar to something I had to do a few years ago.Running a RF Punch 4ch amp and wanted to bridge it for the front door woofers.I contacted RF tech support and guy told me that just feeding the amp 2 channels of input and setting the input switch to "2ch mode" would not work because the outputs would all be mono.So from the DSP I had to use Y-splitters feeding half the amp the left signal and the other half the right signal.Set input switch to "4ch mode" and this kept everything playing in stereo.
That doesn't sound right. Channels 1+2 should receive a signal from the L input, and Channels 3+4 should receive the R input. Now if, for some reason, the L signal was routed to Channel 1+4 and R went to 2+3, then the L and R inputs would be summed to mono. But I can't see any reason they would design the amp that way. And even if they did, u could still bridge 1+4 for the L speaker and 2+3 for the right speaker. Do u have a model #?

Getting back to the Kenwood in question, it looks like they cheaped out on the input switches, and therefore it does not have the ability to send a signal from the A inputs to the B channels :surprised:
 

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This is similar to something I had to do a few years ago.Running a RF Punch 4ch amp and wanted to bridge it for the front door woofers.I contacted RF tech support and guy told me that just feeding the amp 2 channels of input and setting the input switch to "2ch mode" would not work because the outputs would all be mono.So from the DSP I had to use Y-splitters feeding half the amp the left signal and the other half the right signal.Set input switch to "4ch mode" and this kept everything playing in stereo.
That doesn't sound right. Channels 1+2 should receive a signal from the L input, and Channels 3+4 should receive the R input. Now if, for some reason, the L signal was routed to Channel 1+4 and R went to 2+3, then the L and R inputs would be summed to mono. But I can't see any reason they would design the amp that way. And even if they did, u could still bridge 1+4 for the L speaker and 2+3 for the right speaker. Do u have a model #?

Getting back to the Kenwood in question, it looks like they cheaped out on the input switches, and therefore it does not have the ability to send a signal from the A inputs to the B channels
Punch P400x4......like I said,spoke with RF tech support and he assured me I needed Y-splitters.He said 2ch input mode was designed on that amp for running subwoofers only,not mids and highs that need to play in stereo.
 

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What it SHOULD (IMO) do is connect the inputs within channel pairs, rather than across channel pairs. So if u put the amp in 2ch mode and u connect the L RCA to the front inputs, both the L and R inputs on the front would receive a L signal. Then u could bridge the front inputs and use them to run a left-side speaker. Repeat the process for the right and u have a stereo setup. That's how my 4ch amp works when it's in 2ch input mode.

But what u'r telling me is this amp connects the inputs across channel pairs. So the L input on the front channels also provides a signal to the L input on the rear channels, and the same for the R. So u have to leave it in 4ch mode and use Y-splitters so that the L RCA feeds input to both the L and R inputs on the front, and the same for the R RCA on the rear.

The advantage of the way my amp does it is that u don't need Y-splitters to run in 2ch stereo. The advantage I can think of for the way the RF amp does it is that u don't need Y-splitters to run mono bass, which some people believe is better than stereo bass.

Personally, I'd prefer the ability to bridge to stereo. In fact, I'd be playing around w/ the inputs to make sure it really does work the way the tech told u it does.
 
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