3 way capable of high SPL's

deank

Member
2013-01-01 5:16 pm
I heard the active ATC 150's and Geithain 901's and was blown away with low distortion and high SPL's. I tried to go down the diy route read a few forums and built a pair of DQWT's 12 because I didn't have the money for the ATC's and have only a low powered Croft power amp - 50 watts. Unfortunately I had not realised the limit of SPL's from Troel's design and now on speaking with him at length have basically chosen the wrong design. He now says that his QUATTRO will work with a 15 inch bass unit and active crossover - but it won't have the frequency extension of the DQWT 12. I am now realising that no matter how much you read until you build the first pair of loudspeakers there is so much you DON'T understand. Can anyone direct me to some simple 3 way designs that are efficient, neutral and can create high SPL's with good low end extension.
Thanks,
A true beginner!
 

deank

Member
2013-01-01 5:16 pm
Hi,
I would ideally like to keep the Croft 50 watt amplifier but can obtain another pair of monoblocks giving the option of 100 watts bridged or biamped with a split crossover.
In my room I measured 111dB @ 1 metre from the DQWT but this was peak and accompaied by such huge excursion of the midrange unit that I cannot help but feel that long-term this would destroy it. The same levels of sound from the ATC (at their headquarters in Stroud) saw no significant visible excursion of any of the units - and Ben the engineer commented that this was the desireable situation. Sat in my listening seat approximately 10/12 foot away a hand held SPL meter gave peaks of around 105 dB. I would like to make it clear that I listen only occasionally at this kind of level - perhaps once or twice a week for perhaps 10-30 minutes - usually with music like Paul Gilbert and Racer X trying to re-create that "live" feeling.
Budget I would say would be around £1500 for the units. I am happy to entertain an enclosure around the 150-200 litre mark.
Your opinions are very valuable.
 
JBL 2226, 6th order ported (about 60L net for 40Hz), B&C 8NDL51, B&C DE250 on a SEOS12 WG, active of course.

Last time I looked DIY Sound Group (SEOS wave guide) do not ship to Europe and if they do by now postage, duty and tax will make them very expensive.

You could build something like Daniel Hertz M1s for around £1500 (M1s retail for about 100k!).
The drivers add up to about £1200 and are all made by Beyma which are easily available from Blue Aran or LMC (LMC Audio Systems Webshop).
LMC has branches in London and Birmingham.
 
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Jay1111

Member
2013-02-14 6:16 am
AZ
Hi,
I would ideally like to keep the Croft 50 watt amplifier but can obtain another pair of monoblocks giving the option of 100 watts bridged or biamped with a split crossover.
In my room I measured 111dB @ 1 metre from the DQWT but this was peak and accompaied by such huge excursion of the midrange unit that I cannot help but feel that long-term this would destroy it. The same levels of sound from the ATC (at their headquarters in Stroud) saw no significant visible excursion of any of the units - and Ben the engineer commented that this was the desireable situation. Sat in my listening seat approximately 10/12 foot away a hand held SPL meter gave peaks of around 105 dB. I would like to make it clear that I listen only occasionally at this kind of level - perhaps once or twice a week for perhaps 10-30 minutes - usually with music like Paul Gilbert and Racer X trying to re-create that "live" feeling.
Budget I would say would be around £1500 for the units. I am happy to entertain an enclosure around the 150-200 litre mark.
Your opinions are very valuable.

I think zaph's sb12.3 could handle that kind of output for under your budget, but I think you would need a more powerful amp.
 
Hi deank,

I haven't built them myself but the fact that the M1s use Beyma drivers has come up in another thread. I think possibly with actual driver identification. They came up to £1200 for the pair plus VAT ;-(

You might have to search either here or on the interweb in general.
Unless your room is really rather large I think it should be possible to get away with a 15+8 instead of 18+12 and cross to 90x40 horn rather than a 60x40.

I would definitely use an active crossover at least between bass and mid+tweeter.
 
Must it be a 3-way?

A lot of DIY's and others use a 15" woofer and a 1" CD with appropriate horn. Do a search and you'll find dozen's of different takes on this solution.

I for one would really recommend using a WG instead of a horn. The producer of the SEOS in Poland (Autotech) also makes other good alternatives.

If not going for an existing design like the Pi4 or JBL 4430 I'd recommend that you use a good sounding active crossover, preferably with EQ-possibilities. A CD with horn or WG can take some work to get properly integrated in a system.
 
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deank

Member
2013-01-01 5:16 pm
The simplicity of a 2 way does appeal.
If one uses a tried design like the 4430 what units would you use to make a "clone" - presuming that an original is not available and I don't want to use secondhand units.
Does it play equally well at low volumes or is it only optimized for loud listening?
The youtube videos of them "sound" interesting!
I cannot use corners I'm afraid.
 
First off I haven't used these drivers but they do seem to have a good reputation with those that have (on here and elsewhere).

For a 4430 'copy' and with a sensible budget in mind I'd be looking at these drivers:

FaitalPro 15FH500 at £179.95

FaitalPro HF144 1.4" compression driver at £144.95
(both from lean-business.co.uk)

RCF HF99 horn (found a dutch seller €52)

crossed active at around 900Hz.

If you want more bass/volume you can just double up on woofers, 4435-like.
 

deank

Member
2013-01-01 5:16 pm
If I use a SEOS 15 from Autotech with a B&C DE 250 how do I fix the 2 items together - without drilling holes in the front of the waveguide?
I intend to use the JBL L2226h as the bass unit - would you use an active crossover or go for an "off the shelf" product like Wayne Parham's crossover?
Do you expect this speaker to sound good at low volumes?
 
I heard the active ATC 150's and Geithain 901's and was blown away with low distortion and high SPL's. I tried to go down the diy route read a few forums and built a pair of DQWT's 12 because I didn't have the money for the ATC's and have only a low powered Croft power amp - 50 watts. Unfortunately I had not realised the limit of SPL's from Troel's design and now on speaking with him at length have basically chosen the wrong design. He now says that his QUATTRO will work with a 15 inch bass unit and active crossover - but it won't have the frequency extension of the DQWT 12. I am now realising that no matter how much you read until you build the first pair of loudspeakers there is so much you DON'T understand. Can anyone direct me to some simple 3 way designs that are efficient, neutral and can create high SPL's with good low end extension.
Thanks,
A true beginner!

Define High SPL's..?

Hi,

In my room I measured 111dB @ 1 metre from the DQWT but this was peak and accompaied by such huge excursion of the midrange unit that I cannot help but feel that long-term this would destroy it. The same levels of sound from the ATC (at their headquarters in Stroud) saw no significant visible excursion of any of the units - and Ben the engineer commented that this was the desireable situation. Sat in my listening seat approximately 10/12 foot away a hand held SPL meter gave peaks of around 105 dB. I would like to make it clear that I listen only occasionally at this kind of level - perhaps once or twice a week for perhaps 10-30 minutes - usually with music like Paul Gilbert and Racer X trying to re-create that "live" feeling.

Err OK, so you are sitting 4M away or 1 M away ...?
 

deank

Member
2013-01-01 5:16 pm
I am sitting 10/12 foot away to listen.
Sat down if I measure SPL with a hand held meter it measures 105dB at a level that I consider a high SPL.
If I then place the SPL meter at 1m from the speaker and measure the same peaks the highest is 111dB. At this level my Troel Gravesen DQWT exhibited very large excursions of the JA8008 - as this unit takes most of the bass frequencies.
I have read of many "studio monitors" that are capable of producing 116-130dB for EXTENDED periods and I guess that this seems a safer option for me if the speakers are to last.
As I said this level is occasional but when I turn up the volume I don't want to then find that I have destroyed the speakers.
I have not defined high SPL's as it would appear to mean different things to different people - I can objectively measure and convey to this forum what I consider high SPL.
 
Youre basing your assumptions on excursion? If your in a linear range, then you aren't shortening the life of your speaker, especially.

I would try to audition econowave solutions, but if your happy with the way your current speakers sound and are certain that they are undistorted, blast away. They might last 20% less time than just sitting around, but really the ozone in the air might rot them faster then "exercising" them in their linear range.

That said, the high efficiency 2 way designs, have real advantages, especially in peak spl.
 
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