xpr-5s for infra bass?

[anjora]

I am looking for amps capable of driving 16 15inch woofers(dayton rss390hf-4 or better), i will then need a total of at least 4000 watts. of course the drivers will be in sealed enclosure, i will the need some boost at the lower frequencies to obtain flat frequency response down to 4hz, the room should provide some gain there as well.

i think i will built the active crossover, eq circuit for myself and do measurements until I obtain flat frequency response and correct phase 4hz...40khz(this will result in very good impulse response).

[edoggrc51]

For that kind of woofage you should be looking at pro-amps.

[sharkman]

pro amps, and some kind of class D. I'm not familiar with 'infra' bass. What is that?

[edoggrc51]

Infra bass is basically bass you don't hear just feel. So pretty much anything under 20hz.

[bulldozer]

16 xpa-1's would surely do the job.

[bond007]

or go with some XPR-1's

[bond007]

or xpa-1's will work to good luck on that.

[Jim]

If you're looking at that....... A pair of Behringer EP2500/EP4000 would go far. They're used in an number of Infinite Baffle installs and the like.

Or invest in some good Crown or QSC amps.

[sharkman]

Dec 30, 2012 16:29:40 GMT -5 anjora said:

I am looking for amps capable of driving 16 15inch woofers(dayton rss390hf-4 or better), i will then need a total of at least 4000 watts. of course the drivers will be in sealed enclosure, i will the need some boost at the lower frequencies to obtain flat frequency response down to 4hz, the room should provide some gain there as well.

i think i will built the active crossover, eq circuit for myself and do measurements until I obtain flat frequency response and correct phase 4hz...40khz(this will result in very good impulse response).

Am i missing something, or are you hoping to get output down to 4 Hz? I've also never heard of anything so low! Is it hard to do?

[anjora]

actually i have considered pro amps(class D) but xpr-5 seams to have good value and it has fan-less design, i would also be able to use one amp module from each xpr-5 to drive a front speaker.

with pro amps the solution would be to get a 2 or 4 channel amps and being able to have maximum use of the power supply. another sulution would be 5 xpr-2:s but it's a litle bit expensive for my taste. unfortunately pro amps usually doesn't live up to their specifications.

the driver dayton rss390hf-4 is rated to handle 500w so with 16 drivers 8000 watts would to reach the specifications of that particlular driver. yes i am serius with 4hz, the room gains should be pretty high down there.

[garbulky]

I don't think the emo amps are marketed as amps for passive subs...

[harri009]

I guess I am not 100% on how you plan to connect the 16 speakers to an XPR-5. Are you planning to run them in series? If in series to show the amp an 8ohm load (2 of those 4 ohm subs per channel) this would still only give you 10 subs correct? I am not a car audio guy so not use to having to play the load game but could you elaborate on your plan?

[briank]

I would go with pro amps as Edogg recommended. I like Crown amps.

[anjora]

Dec 31, 2012 10:47:15 GMT -5 harri009 said:

I guess I am not 100% on how you plan to connect the 16 speakers to an XPR-5. Are you planning to run them in series? If in series to show the amp an 8ohm load (2 of those 4 ohm subs per channel) this would still only give you 10 subs correct? I am not a car audio guy so not use to having to play the load game but could you elaborate on your plan?

with a pair xpr-5:s it would be 2 subs per amp module, rss390hf-4 is a 4 ohm driver and connected in parallel the result would be 2 ohm load(i am considering other drivers as well). 1 amp module/channel per xpr-5 would then be used for the speakers.

xpr-5 has a 3300VA power supply, so the maximum output should be around 6000 watts total, luckily i live in Sweden so the maximum output from 2 a 20A fuses would be 2*20*230 = 9200W so I don't think pro amps would provide that much more power, but it would of course be cheaper.

[jackfish]

I would connect them in series for an 8 Ohm load. While the XPR-5 may handle a 2 Ohm dip there are likely to be frequencies at which those drivers in parallel will cause impedance to drop below 2 Ohms which will likely cause a fault shutdown.

How are you going to get 4 Hz from sixteen 15" drivers each with an Fs of 18 Hz? In addition, the XPR-5 will likely reproduce 4 Hz, but probably without much current.

[anjora]

Dec 31, 2012 12:27:05 GMT -5 jackfish said:

I would connect them in series for an 8 Ohm load. While the XPR-5 may handle a 2 Ohm dip there are likely to be frequencies at which those drivers in parallel will cause impedance to drop below 2 Ohms which will likely cause a fault shutdown.

How are you going to get 4 Hz from sixteen 15" drivers each with an Fs of 18 Hz? In addition, the XPR-5 will likely reproduce 4 Hz, but probably without much current.

yes a 8 ohm driver would be more optimal since the impeedance in paralell would be 4 then. this is how i would connect 16 drivers

[DYohn]

4 X 8-ohm drivers in parallel creates a net 2-ohm load. Before you worry about how to power 16 woofers, I'd like to know how and where you plan to mount them? Where are you placing them in the room? I don't know if you've modeled them but to achieve usable SPL @ 4-Hz, you need a different driver than the Dayton, especially in a "sealed" enclosure.

[anjora]

Dec 31, 2012 14:07:36 GMT -5 DYohn said:

4 X 8-ohm drivers in parallel creates a net 2-ohm load. Before you worry about how to power 16 woofers, I'd like to know how and where you plan to mount them? Where are you placing them in the room? I don't know if you've modeled them but to achieve usable SPL @ 4-Hz, you need a different driver than the Dayton, especially in a "sealed" enclosure.

there isn't any driver on the market capable of it without some boost, 16 drivers provides 24dB more eq headroom than a single driver. I haven't bough any drivers or anything. the dayton 15 is a budget driver that still performs very measures good but it can only handle 500w, connecting two drivers in series would only 200 emotiva watts per driver which isn't enough.

the sub would be standing and with 4 drivers each it would be 1.6m tall, the box would have to be pretty large to keep the intermodulated distortion low(100 times the amount of air moved by the drivers at one direction). I have looked at some other builts and I count with at least 12dB of room gain at 4hz. if the room gain is 2dB at 20hz 4hz would require 62.5 times more power, the intensity of such low tones is generally very low so i don't see any major problem(besides cost).

[DYohn]

What you want is an infinite baffle system. Don't use the RS series woofers, if you want to use Dayton drivers use their 15" IB series, partnumber 295-455. If it was me building such a system, I'd use Acoustic Elegance IB series drivers, www.aespeakers.com/drivers.php?driver_id=8

[knucklehead]

Either an infinite baffle or a 'tuba' horn setup would work but the tuba horn would be a monster with that many drivers. You'd need a barn-sized room to contain it. The infinite baffle can be constructed in an outside or crawl space using a containing manifold vented to the listening room. Finding that much outside wall space to mount all the drivers directly onto the listening wall could be a problem and would probably be an eyesore as well. A manifold vented into the listening room and sealed off from leaks could get you some seriously tactile bass with that many drivers. It may well play havoc with ear pressure on sensitive ears too.