Passive Crossover for Sub

jakelm

I'm having an issue with my Hk 635 avr. It just not crossing over the subs like I want it to. It seems to be holding a flat responce all the way up to 120hz before rolling off @12dbs/octive. I have the sub crossover point on the reciever set to 60hz. And I still get a spike between 90 and 110hz. I get the same responce no matter what crossover point I use. So something is going on with the reciever.

I have 2 subs hooked to a vintage Hafler amp, via subwoofer preout. Im thinking of building (if possible) a passive sub crossover. Something that rolls off between 12 and 24 dbs/octive @ around 70-80hz with no highpass filter. Any suggestions?

Jake

jm1

jakelm wrote:

... And I still get a spike between 90 and 110hz. I get the same responce no matter what crossover point I use. ...

Could this be a room mode issue since it appears regardless what you do? Have you tried to reposition your speakers/subs and listening position to see if you can reduce the spike?

jakelm

Jm, If the crossover point is set to 60hz, I would think if a 100hz signal is sent, no audible sound would apear as strong as 40-70hz. I had this same setup with my older Onkyo502, when I would run a sub test with crossover set on the reciever to 60hz, I would get little to no sound out of the subs above 80hz or so, much less an increase in dbs @ or around 100hz.

Jake

jakelm

I'm thinking of going with this bash amp and changing the bass boost resistors to my liking http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=300-750

and just putting my Hafler on my Polk 7b's.

What do you all think?

My subs consist of a 3.7cuft encloser with a 3" port 11"long. I curently have a Dyaton 12" 4ohm DVC in that encloser. I have a SVS 12.1 that I will swop with the Dayton when the SVS comes in. Then put the Dayton in a 3.0 PE encloser with a similar port and similar amp.

Jake

P.S Does anyone have any experience with this Bash amp?

jakelm

Also, would you know if this bash amp is similar to the one that SVS uses?

Gaara

Harrison Labs makes passive crossovers called FMODs, you just hook them up inline with the cable going to the sub amp. Can be found at parts express, for example 70 hz low pass

Jared

jakelm

Thanks Gaara, Just an update. I have desided to put my Hafler on the 7b's and get the BASH 300s plate amp from PE. But if I were to go with another external amp, that would be a great buy. Thanks for your input.

Jake