8 Questions for you - high-end sub design...

[unknownuser]

I want to make a high quality sub for a mid to high end HT/hi fi set-up.

Here's a number of questions for you. See if you can resolve my worries about this project???

1) I was planning on using two 12" drivers (so that I never really ever run out of headroom, excursion and minimise distorsion). Is this really overkill for a good set-up in a room 18ft x 25 ft.

2) Would it sound better balanced with two 10" drivers?

3) Does anyone have any suggestions as to how I should configure two PE Ref 12" HF drivers into a single cabinet (3cu ft or less).

I am planning to use a 1000w digital amp to driver them both and are open to either sealed or a ported cabinet.

I want good extension but sound quality is my fist priority so sealed seems to be the way to go as far as I can see (for tight, clean and accurate bass) for HT and hifi use.

4) Can this driver be mounted at the base of the sub?

5) Does this affect the coil alignment in the magnet and thus performance?

6) How does this driver compare to both the PE titanic 3 and Peerless XLS 12's?

7) Will these drivers (with xmax from 12 to 18mm one way travel) sound better than the ultra high excusion comp auto sub drivers I have seen with >75mm peak to peak xmax?

8) Finally, are all these cone sub drivers simply going to be redundant following the arrival the Tymphany LAT sub driver later in the year? Certainly seems that way given its performance/size reports.

See :

<A HREF="http://www.pcmag.com/article2/">www.pcmag.com/article2/</A> 0,1759,1749044,00.asp

Some to the point answers on the above questions would be appreciated very much before I go and spend my money and build a dud.

Thanks all.

J




(Originally posted by: Jimo Burnside)

[mikebw]

Allow me to outline your goals independently of how they will be affected by individual parts-

It sounds like you want a home theater / hifi system, for an 18x25 ft. room, with a focus on sound quality over deep low-end response.

Two things you don't mention are cost/budget, and how much space is an issue.

> 1) I was planning on using two 12"
> drivers (so that I never really ever run out
> of headroom, excursion and minimise
> distorsion). Is this really overkill for a
> good set-up in a room 18ft x 25 ft.

I don't think you need two separate drivers to meet this need, although some people like 'stereo-bass'.

> 2) Would it sound better balanced with two
> 10" drivers?

Hard to quantify that either way. Probably what it will come down to is finding the right driver for the size enclosure you want, that can perform at the levels you want to achieve. The design of the enclosure will dictate to a large degree what the frequency response curve will look like.

> 7) Will these drivers (with xmax from 12 to
> 18mm one way travel) sound better than the
> ultra high excusion comp auto sub drivers I
> have seen with >75mm peak to peak xmax?

Again, 'sound better' is not really a useful term to compare speakers with. With most large xmax drivers I think the goal is huge SPL and low-end excursion, the least of which is sound quality.

[shawn_a]

This probably won't answer all your questions but here's a quick-hit summary. Yes, two of the RSS315HF subs will work well enough in a 3 ft^3 sealed enclosure. I wouldn't hesitate to try it myself. When you say mount in the base of a sub, do you mean have the drivers downfiring? That is pointing towards the floor. If so, I would balk at it myself but without running the numbers for the sag percentage I can't give you a thumbs up or down. My personal taste would say it's a sin to hide those beautiful cones but you might disagree.

And as for the 1000W amp, good choice. Just remember to wire the subs in series. The amp probably won't like a 2 ohm load.

The sound quality should be phenomenal for you. I installed my 12" HF in a ported enclosure and the bottom end is very clear and accurate. I wouldn't worry about overkill. You can always fiddle with the PEQ on the amp and balance things out with the gain knob and your receiver.

Good luck on your decision. It's a tough one to make but out of the three drivers you listed, I feel the RS would do you best.

shawn

[matthewkolson]

18x25 room... how much output do you need? Personally I'd go with 4 of the 12" HF woofers, or more. but thats just me. Those 1000 watt digital amps are just fine. 18x25 is kinda big for dual 12's in my opinion...but i'm a big fan of overkill... 2 12's is for sure not overkill in a room like that. later

-Matthew K. Olson DMD

[unknownuser]

Provided Link: http://www.mtxaudio.com/caraudio/pro...jackHammer.cfm


> Thanks guy's,

I think I'll start with a front loaded (yes they look nice the drivers), sealed cabinet with dual drivers and the 1000w amp.

Thats a good start for me. If I need to (which I doubt), i can add another I'll do it when funds allow.

seems to me that the Typmphany LAT's are going to change sub design. Check this link out. Looks like production models are on the way soon!! Wonder how much they cost??

<A HREF="http://www.tymphany.com/products_Tymphany_LAT.html">http://www.tymphany.com/products_Tymphany_LAT.html</A>

also.... have you seen the MTX JackHammer 22???

Madest, badest sub ever for sure..take a look at this. and I thought the top of the line pioneer comp sub was mad.

<A HREF="http://www.mtxaudio.com/caraudio/pro...jackHammer.cfm">http://www.mtxaudio.com/caraudio/pro...jackHammer.cfm</A>

Thanks for the feedback guy's.




(Originally posted by: Jimo Burnside)

[jonpike]

> I want to make a high quality sub for a mid
> to high end HT/hi fi set-up.

> Here's a number of questions for you. See if
> you can resolve my worries about this
> project???

> 3) Does anyone have any suggestions as to
> how I should configure two PE Ref 12"
> HF drivers into a single cabinet (3cu ft or
> less).

> I am planning to use a 1000w digital amp to
> driver them both and are open to either
> sealed or a ported cabinet.

It might be an idea to try two enclosures, with 500W amps, in different parts of the room. This could result in better bass over more of the room, depending on placement, etc. Downside is two boxes to integrate into your decor..

> 6) How does this driver compare to both the
> PE titanic 3 and Peerless XLS 12's?

> 7) Will these drivers (with xmax from 12 to
> 18mm one way travel) sound better than the
> ultra high excusion comp auto sub drivers I
> have seen with >75mm peak to peak xmax?

I've only heard the 10", but reading all the reports, it seems to shape up very well against the one you mention. The RS subs are very clean, if not the ultra massive airmovers that the othes are. Sounds like you are searching for clean over sheer power, anyway.

[johnnyrichards]

> I think I'll start with a front loaded (yes
> they look nice the drivers), sealed cabinet
> with dual drivers and the 1000w amp.

> Thats a good start for me. If I need to
> (which I doubt), i can add another I'll do
> it when funds allow.

> seems to me that the Typmphany LAT's are
> going to change sub design. Check this link
> out. Looks like production models are on the
> way soon!! Wonder how much they cost??

>
> <A HREF="http://www.tymphany.com/products_Tymphany_LAT.html">http://www.tymphany.com/products_Tymphany_LAT.html</A>
> also.... have you seen the MTX JackHammer
> 22???

> Madest, badest sub ever for sure..take a
> look at this. and I thought the top of the
> line pioneer comp sub was mad.

>
> <A HREF="http://www.mtxaudio.com/caraudio/pro...jackHammer.cfm">http://www.mtxaudio.com/caraudio/pro...jackHammer.cfm</A>
> Thanks for the feedback guy's.

One of those JackHammers with 2 1000 W amps would definately make a statement the neighbors would not appreciate....

[duanebrown]

Provided Link: http://www.tymphany.com/products_Tymphany_LAT.html


> I want to make a high quality sub for a mid
> to high end HT/hi fi set-up.

> Here's a number of questions for you. See if
> you can resolve my worries about this
> project???

> 1) I was planning on using two 12"
> drivers (so that I never really ever run out
> of headroom, excursion and minimise
> distorsion). Is this really overkill for a
> good set-up in a room 18ft x 25 ft.
no

> 2) Would it sound better balanced with two
> 10" drivers?
no

> 3) Does anyone have any suggestions as to
> how I should configure two PE Ref 12"
> HF drivers into a single cabinet (3cu ft or
> less).
I wouldn't do it, well if I could use two 1.5cf boxes instead I would do that over one every time.
having two subs helps to even out room modes.

> I am planning to use a 1000w digital amp to
> driver them both and are open to either
> sealed or a ported cabinet.
> I want good extension but sound quality is
> my fist priority so sealed seems to be the
> way to go as far as I can see (for tight,
> clean and accurate bass) for HT and hifi
> use.
Very good, and you can eq more low end if needed for HT.

> 4) Can this driver be mounted at the base of
> the sub?
Don't know.

> 5) Does this affect the coil alignment in
> the magnet and thus performance?
Yes, but how much is the follow up Q. - A. I don't know!

> 6) How does this driver compare to both the
> PE titanic 3 and Peerless XLS 12's?
IMHO, Titanic is for SPL not SQ, XLS's are made to be used with a PR. SQ and SPL are close between the XLS and RS.

> 7) Will these drivers (with xmax from 12 to
> 18mm one way travel) sound better than the
> ultra high excusion comp auto sub drivers I
> have seen with >75mm peak to peak xmax?
Yes, aside from a JL Audio W7, SPL is the biggest concern, I think marketing is also a huge factor here.

> 8) Finally, are all these cone sub drivers
> simply going to be redundant following the
> arrival the Tymphany LAT sub driver later in
> the year? Certainly seems that way given its
> performance/size reports.
sure, and bose is the best! Honestly I don't think so, we'll have to wait and see. Just guessing that spl per $ won't be very good.

> See :

> <A HREF="http://www.pcmag.com/article2/">www.pcmag.com/article2/</A>
> 0,1759,1749044,00.asp

> Some to the point answers on the above
> questions would be appreciated very much
> before I go and spend my money and build a
> dud.

> Thanks all.

> J

[mikebw]

That sub is retarted-sick, and I mean that in both good and bad ways.

Posted on the forum before, the specs are just off the charts. Surely you could reproduce the same SPL's, and frequencies with a few smaller drivers with less power.

<A HREF="http://www.mtxaudio.com/caraudio/pro...jackHammer.cfm">http://www.mtxaudio.com/caraudio/pro...jackHammer.cfm</A>
> Thanks for the feedback guy's.

[unknownuser]

Provided Link: http://www.mtxaudio.com/caraudio/pro...jackHammer.cfm


> Thanks guy's,

I think I'll start with a front loaded (yes they look nice the drivers), sealed cabinet with dual drivers and the 1000w amp.

Thats a good start for me. If I need to (which I doubt), i can add another I'll do it when funds allow.

seems to me that the Typmphany LAT's are going to change sub design. Check this link out. Looks like production models are on the way soon!! Wonder how much they cost??

<A HREF="http://www.tymphany.com/products_Tymphany_LAT.html">http://www.tymphany.com/products_Tymphany_LAT.html</A>

also.... have you seen the MTX JackHammer 22???

Madest, badest sub ever for sure..take a look at this. and I thought the top of the line pioneer comp sub was mad.

<A HREF="http://www.mtxaudio.com/caraudio/pro...jackHammer.cfm">http://www.mtxaudio.com/caraudio/pro...jackHammer.cfm</A>

Thanks for the feedback guy's.




(Originally posted by: Jimo Burnside)

[johnnyrichards]

> That sub is retarted-sick, and I mean that
> in both good and bad ways.

> Posted on the forum before, the specs are
> just off the charts. Surely you could
> reproduce the same SPL's, and frequencies
> with a few smaller drivers with less power.

>
> <A HREF="http://www.mtxaudio.com/caraudio/pro...jackHammer.cfm">http://www.mtxaudio.com/caraudio/pro...jackHammer.cfm</A>

Yes you could, but would you have the option of saying to your friends "My HT has two 22" subwoofers. How do your 12 10's stack up?"

[bogie]

FWIW, I've got two ported (5.5/18.5hz) 15" quatro/240 subs in The Bunker, and two sealed 3 cube 15" Quatro/100 watt subs under my maggie MMGs in my living room.

> I want to make a high quality sub for a mid
> to high end HT/hi fi set-up.

> Here's a number of questions for you. See if
> you can resolve my worries about this
> project???

> 1) I was planning on using two 12"
> drivers (so that I never really ever run out
> of headroom, excursion and minimise
> distorsion). Is this really overkill for a
> good set-up in a room 18ft x 25 ft.

There is no such thing as overkill - You can always not play it as loud, but if you don't have _enough_ sub, it'll sound like crap.

> 2) Would it sound better balanced with two
> 10" drivers?

You won't be able to go as low.

> 3) Does anyone have any suggestions as to
> how I should configure two PE Ref 12"
> HF drivers into a single cabinet (3cu ft or
> less).

Why a single cabinet? Duals will give you more versatility. Also, remember that there's no replacement for displacement.

> I am planning to use a 1000w digital amp to
> driver them both and are open to either
> sealed or a ported cabinet.

With those drivers, you may want more power.

Also, don't just think "sealed" or "ported." It sounds like your wife's gonna kill you if you have a big ol' box in the room, right? There's always the infinite baffle concept. At the other end, don't discount the transmission line...

> I want good extension but sound quality is
> my fist priority so sealed seems to be the
> way to go as far as I can see (for tight,
> clean and accurate bass) for HT and hifi
> use.

Infinite baffle, transmission line, sealed, ported, in that order.

> 4) Can this driver be mounted at the base of
> the sub?

I'm not sure.

> 5) Does this affect the coil alignment in
> the magnet and thus performance?

> 6) How does this driver compare to both the
> PE titanic 3 and Peerless XLS 12's?

> 7) Will these drivers (with xmax from 12 to
> 18mm one way travel) sound better than the
> ultra high excusion comp auto sub drivers I
> have seen with >75mm peak to peak xmax?

More than likely - it isn't all about da xmax...

> 8) Finally, are all these cone sub drivers
> simply going to be redundant following the
> arrival the Tymphany LAT sub driver later in
> the year? Certainly seems that way given its
> performance/size reports.

> See :

> <A HREF="http://www.pcmag.com/article2/">www.pcmag.com/article2/</A>
> 0,1759,1749044,00.asp

> Some to the point answers on the above
> questions would be appreciated very much
> before I go and spend my money and build a
> dud.

[bogie]

If you don't have to worry about something large, build yourself a pair of towers of either 8" or 10" drivers (8" probably easier on space). Won't play quite as low, but it'll be "faster."

[bogie]

Do you want something that'll provide random thumps/booms, or do you want something that'll be nice and tight, and get so low you can't hear it (but you'll feel it...) - this ain't car audio...

The Tymphany stuff been done already... Altho it does look like an interesting concept. A line array of 8 8" drivers could be interesting.

> I think I'll start with a front loaded (yes
> they look nice the drivers), sealed cabinet
> with dual drivers and the 1000w amp.

> Thats a good start for me. If I need to
> (which I doubt), i can add another I'll do
> it when funds allow.

> seems to me that the Typmphany LAT's are
> going to change sub design. Check this link
> out. Looks like production models are on the
> way soon!! Wonder how much they cost??

>
> <A HREF="http://www.tymphany.com/products_Tymphany_LAT.html">http://www.tymphany.com/products_Tymphany_LAT.html</A>
> also.... have you seen the MTX JackHammer
> 22???

> Madest, badest sub ever for sure..take a
> look at this. and I thought the top of the
> line pioneer comp sub was mad.

>
> <A HREF="http://www.mtxaudio.com/caraudio/pro...jackHammer.cfm">http://www.mtxaudio.com/caraudio/pro...jackHammer.cfm</A>
> Thanks for the feedback guy's.

[rory]

It is going to be tough to find a plate amp that is 2 ohm stable. I discussed it with PE Darren a while back and he says that seems like a niche that needs to be filled.

So, Why can't you just use an off the shelf 1000W plate amp? Because when you wire in series, the combined resistance (referred to as "impedance" because it changes slightly with frequency) cuts in half, so the amplifier can push current twice as easily, and you wind up with an amp that's 2000W into 2 ohms. But the problem is that all plate amps that I've found for sale today are only stable into impedances down to 4 ohms. Why? Because their power supplies are probably not capable of supplying enough current for 2000W. Also, when an amp is trying to push twice the current, it generates four times as much heat. This usually causes the amp to go into thermal (overtemperature) protection quickly.

What happens when you wire two drivers in series? The voltage the amplifier is supplying is still the same, but the resistance (impedance) is doubled. Therefore the actual current the amplifier can push across the voice coil is half of what it can do at its rated impedance, and your 1000W amplifier will only put out about 500W.

I suggest looking for a bigger, beefier driver if you suspect your application calls for two of the smaller drivers. One option to look at is the Titanic MkIII which will handle 1000W and has a 4 ohm impedance. Another option that you might consider (from another woofer company) is the AE Speakers AV15. I have the 12" version of this woofer and it is phenomenal. The AV15 will displace 2.2 times more air than one 12" RS series subwoofer, which would make it about equivalent to two RS series subwoofers. The 15" woofer is also more efficient as well, and people get excellent results with only 500 watts. Also, SoundSplinter.com has some woofers that are being used by home enthusiasts for project subs. So you're not limited to the woofers Parts Express has for sale, either. You've got many options.

[jj]

> I want to make a high quality sub for a mid
> to high end HT/hi fi set-up.
> I want good extension but sound quality is
> my fist priority so sealed seems to be the
> way to go as far as I can see (for tight,
> clean and accurate bass) for HT and hifi
> use.

If you want clean, deep quality bass the way to get it is with a horn. No direct radiator at any price can touch a good horn. By far the best DIY horn plans available are at <A HREF="http://www.billfitzmaurice.com">www.billfitzmaurice.com</A>, I'd look at the Table Tuba for a moderate size cab, the Tuba 36 if you've got neighbors that you really hate.

[Paul O]

MTX Jackhammer... curiously the sensitivity specs are missing. You can probably safely assume it's down in the mid 80's. Big whoop!! Lots of other drivers out there that'll do the same with a fraction of the power.. and cost!!

Tymphany Lat... Pleeeeease!! Can anybody say BOSE!!! If space saving is your goal, and you want the acoustic illusion of having a sub, then this is the ticket. I don't believe for a minute it'll compete with a pair of 12's for low end extension.

[hongrn]

Here are twin towers for "stereo bass" (just kidding), using RS 10" subs and 12" PRs, each powered by 300W BASH plate amps. If you want clean bass for music, and loud LFEs for HT, this is a good combination. My new HT room will be 13x23, but I suspect these will make themselves loud and clear. The subs are in 1.5 cuft enclosures with a F3 of 25Hz.

Hong

[bogie]

> Tymphany Lat... Pleeeeease!! Can anybody say
> BOSE!!! If space saving is your goal, and
> you want the acoustic illusion of having a
> sub, then this is the ticket. I don't
> believe for a minute it'll compete with a
> pair of 12's for low end extension.

Yeah, it basically looks like they've tried to cram more drivers into an array by putting 'em in backwards and sideways (gotta wonder about what effect that'll have...), with essentially small enclosures - or they may be vertical dipoles? Yeech... At any rate, there is no replacement for displacement. I like the "tightness" of the bass I get from my maggies, but they roll off at about 50hz... My Q15s, with the xovers dialed way low, fill it in very nicely.

[dastardly]

Coolness. I have been thinking along those lines for a relatively small sub that plays low enough and loud enough. Good to see it work out for some one. A 16" cube is pretty small for a subwoofer. Now I just need to wait for the money.

> Here are twin towers for "stereo
> bass" (just kidding), using RS 10"
> subs and 12" PRs, each powered by 300W
> BASH plate amps. If you want clean bass for
> music, and loud LFEs for HT, this is a good
> combination. My new HT room will be 13x23,
> but I suspect these will make themselves
> loud and clear. The subs are in 1.5 cuft
> enclosures with a F3 of 25Hz.

> Hong