Best slam and punch in the bass for hifi (not PA): TH with 15 OR 2x15 BR OR 1x18 BR?

[pk]

Hi,
I consider a bass system for a 3-way, efficient rock rig. It’s for high quality music listening at home - not PA. I primarily listen to rock music. Goals for the bass system:

• Shall cover the 35-150 Hz range
• Max 230 liters net (or app. 8.1 cubic feet) per side
• > 95 dB efficient, preferably higher
• Serious punch and slam with a lot of ‘weight’ with kick drums etc.

I have considered either:

1. A tapped horn with a single 15” woofer (e.g., Eminence 4015LF/3015LF, B&C 15TBX100)

2. A vented box loaded with 2 x 15 woofers (e.g. B&C 15TBX100, Ciare 15.00 SW, or AE TH15H)

3. A vented box loaded with a single 18” woofer (e.g., 18Sound 18LW1400, B&C 18TBX100, Eminence 4018LF, Ciare 18.00 SW, or Precision Devices PD.186)

At the moment I have a 180 watts (8 Ohm) SS amp for the bass and use active filters, but I may consider going for a bigger amp.

Which of the above suggestions would be best considering my preferences? I would especially appreciate to hear from people who have actually compared some of the possibilities, I consider.

Thanks a lot!

Best regards
Peter

[djn]

Good luck Peter. I think a lot of the sub stuff is personal preffernce. Try listening to other systems to see what you like. BUT, I can tell you that having mutiple subs is the way to go.

[chris661]

Mmm, stereo subwoofers would be better than a larger mono one.

Having two coherant sources for bass in different locations in the room means the effects of the room (peaks and nulls) are cut back somewhat, leading to a smoother response at the listening position.

What will these be crossed over to?

[Ellenic]

Hello 2x15 is always better than 1x15 in punch and db.You will have though to make sure you use the same woofers in order to get higher db's.
If you use 2 different woofers db is going down.
I think 2 of the same kind is 2 to 3 db up and 2 different speakers is 2 to 3 db down.
Also 18'' is a good choise as well.
Consider that the more power you want in watts the less quality you ll have,
(unless you go for expensive 3 way systems line array etc...)
You ll have to find the perfect balance for the space you want to hear music.
Are you gonna play the subs mono or stereo?
Although stereo is good for listening, mono in bass has always more punch.

[AndrewT]

Originally Posted by pk

At the moment I have a 180 watts (8 Ohm) SS amp for the bass and use active filters, but I may consider going for a bigger amp.

I would very strongly suggest you don't go bigger in the amplifier department.
Go for more amplifiers.
Two 180W amplifiers give you an extra 3dB capability.
Four 180W amplifiers give you an extra 6dB capability.

Dedicate one amplifier to every driver. If you have two double 15"s for the stereo bass channels then you can use 4off 50W amplifiers.
with 95dB/W @ 1m speakers, you will have the capability of maximum SPL of ~113dB @ 2.5m listening distance. This is loud for home listening.
If you replace the 50W amps with 180W amps you gain a further 5dB for 118dB @ 2.5m

But there is a flaw.
I have used the figures you have given and assumed that 95dB/W @ 1m is available at all frequencies in your desired pass band of 35 to 150Hz.
You will almost certainly find that you cannot afford the space nor the money to give you 95dB/W @ 1m @ 35Hz.

[djk]

This is PA:

http://i56.photobucket.com/albums/g1...CoePA-2009.jpg

This is a home version of the PPSL woofer system:

http://www.waveboxes.com/Wave%20G/gi.gif

http://gallery.audioasylum.com/cgi/v...e=&w=644&h=483

http://gallery.audioasylum.com/cgi/v...=&w=1288&h=966

8 cu ft net dual 15 PPSL (as used in the PA above):

http://i56.photobucket.com/albums/g1...ence151269.gif

A 2 cu ft 2nd order sealed box with an F3 of 30hz can only be 0.18% efficient (84.55dB).
A 2 cu ft 4th order vented box with an F3 of 30hz can only be 0.36% efficient (87.56dB).
A 2 cu ft 6th order vented box with an F3 of 30hz can only be 0.90% efficient (91.54dB).

[Scott L]

Greetings,

Given your situation, and what you are asking, I'd use 2x Acoustic Elegance TD15H per side, both woofers facing fowards in a conventional set up, vented. The T/S parameters, if spot on, fit your requirements almost exactly. Be sure to make the vent(s) large enough as to avoid dynamic compression. This setup will bring the house down ! Should I have to mention
sturdy construction of the box is a MUST with plenty of bracing?
Have a great time; I've used a similar set up to this for years!

[IslandPink]

You may not need or want a 15" for the TH - check this thread if you haven't :
Ideas on 35-150(?) HiFi Tapped Horn

[pk]

Djn, chris661, and Ellenic: Thanks for your replies! Just to clarify: The idea is two stereo speakers with a bass ‘module’ in each.

AndrewT: Fb=35 Hz is perfectly adequate, so I still hope it is possible. But you are probably right, that a bigger amp for the bass would be better by all means.

djk: Thanks for replying! I have been intrigued by the PPSL approach for quite some time, and really wish I had the chance to compare the PPSL to a ‘standard double’ vented box without having to actually build the boxes.

One question: On the AA board Les Hudson – who also endorses the PPSL approach - said (IIRC) that they were his favorite system for bass, and that a PPSL was the way to go if the goal was ‘accuracy’, but that PPSL may not be configuration with most ‘slam’. Since I specificly seek the weighty punch, Les’ statement made me hesitate!? Do you think the PPSL have the same punch/weight as conventional BR boxes? (A long time ago I had pair of JBL 250Ti’s and I actually liked the bass from these, although I would like a steroid version of these). Thanks!

Scott L: Thanks for the suggestion. I really wish I had a chance to the AE drivers on this side of the Atlantic!

IslandPink: Thanks for the direction - yes I already saw the thread. I have read quite a bit about TH, but haven’t had a chance to hear one - yet. I may be dead wrong, but somehow doubt that a fairly tight 10” woofer will provide the punch, I’m seeking – even when horn loaded.

Best regards
Peter

[djk]

"One question: On the AA board Les Hudson – who also endorses the PPSL approach - said (IIRC) that they were his favorite system for bass, and that a PPSL was the way to go if the goal was ‘accuracy’, but that PPSL may not be configuration with most ‘slam’. Since I specificly seek the weighty punch, Les’ statement made me hesitate!? Do you think the PPSL have the same punch/weight as conventional BR boxes? (A long time ago I had pair of JBL 250Ti’s and I actually liked the bass from these, although I would like a steroid version of these). Thanks!"

'Slam' is a function of a steep wavefront in the music and the leading edge is all the higher harmonics. The PA stack shown will absolutely knock you flat on dynamic program material, being horn-loaded and time-aligned.

What Les was referring to is the fact that speakers with high 2nd harmonic distortion have high 'jump factor', or 'punch'. I used to build a dual 12 three-way with 2mm x-max drivers that had an incredible amount of that 'jump factor' or 'slam' at low and moderate volume levels. This speaker made everything 'jump' at low levels, but went into compression at high levels.

So, what were you planning on doing for the mids and HF? That will probably determine more of the sound quality that you are looking for, especially with the 150hz crossover point that you infer.