Large format simple two way TD15M w/TPL-150H or GPA604?

[ctrevith]

Thinking about two way mains for home music and home theater. I can add subs later but for the moment would like to make the most out of the two way for both music and movies. I have a DEQX HDP 3.0 that I use but currently have only one amplifier (Atmasphere S-30) so I'm torn between building a passive two way (using the DEQX to correct and equalize the whole speaker), or getting another amp (probably something bigger for the GPA604 or TD15M) and using the DEQX to its full capability.

I'd like to use the TD15M or GPA604 as low as realistically possible. 115db is more than enough in my 22'x36' listening room which has 8' ceilings and opens through the back of the room to the side into an open area kitchen and adjacent living room so I'm not sure I'll get a lot of rm gain. Listening position is 10'-11'. Speakers would have approx 5.5' from front of speaker to rear wall. Seems from other posts either can go into low 30's or high 20's using either ported or PR alignments. I can build a fairly big box but my only limitation is that one side of the box will be within 2-4 inches of an AV cabinet between the speakers so using opposing PRs may not work.

For the high frequency portion of the TD15M I'm thinking of using a Beyma TPL-150H or Beyma CP-385/Nd with suitable waveguide as a second choice and I'm open to other suggestions.

Love to get some suggestions for enclosure and alignment as well as best option for the high frequency section and xover points for the TD-15M.

Thanks for any info

[ctrevith]

bump

Any one who has experience with these drivers have suggestions for enclosures or crossovers?

[tomcat9]

As for the TD15M, here is some recommendations, not all my words, but what I remember when someone else asked a similar question about this driver.

The TD15M would require a fairly large vented box if you plan to get low with it. If you plan to go without a sub-woofer you'll need a larger box. You'll also be limited in the lowest output but for a music only system you'll be fine. Around 4.5-5 cubic foot tuned in the 32-35hz range would work well. It gives a little bit of a shelved off response to the low end that matches well with room gain. I think you'd be quite good in room to 30hz.

Then if you plan on a sub-woofer also, try tuning to the 45hz range. This will do a few things. It will give you back some efficiency in the 45-80hz range and keep the response nearly flat to under 50hz. That gives you plenty of room to play with the xover to the sub from 60-80hz. It also puts any rise in group delay down low enough that it has little effect on the useable range.

[studiotech]

See my thread here:

Beyma tpl-150 + Lambda TD12M's

We are still loving these as mains at our studio, but did NOT like the TPL used under about 1.5KHz. Your opinion or use may vary. The TD12's were perfectly happy that high and John has always said that he prefers the 15s over the 12s. Maybe you should use the horn loaded version of the TPL to help match dispersion at crossover better.

Greg - technician - Phat Planet Recording Studios - Orlando Florida - Audiophile Quality Recording, Mixing, Mastering, Production

[ctrevith]

Originally Posted by studiotech

See my thread here:

Beyma tpl-150 + Lambda TD12M's

We are still loving these as mains at our studio, but did NOT like the TPL used under about 1.5KHz. Your opinion or use may vary. The TD12's were perfectly happy that high and John has always said that he prefers the 15s over the 12s. Maybe you should use the horn loaded version of the TPL to help match dispersion at crossover better.

Greg - technician - Phat Planet Recording Studios - Orlando Florida - Audiophile Quality Recording, Mixing, Mastering, Production

Thanks Greg. Yes, thinking that the TPL-150H horn version would mate better lower, as response graph shows a little fill below 2K. Did you try anything else interesting besides the TPL-150?

[ctrevith]

Originally Posted by tomcat9

As for the TD15M, here is some recommendations, not all my words, but what I remember when someone else asked a similar question about this driver.

The TD15M would require a fairly large vented box if you plan to get low with it. If you plan to go without a sub-woofer you'll need a larger box. You'll also be limited in the lowest output but for a music only system you'll be fine. Around 4.5-5 cubic foot tuned in the 32-35hz range would work well. It gives a little bit of a shelved off response to the low end that matches well with room gain. I think you'd be quite good in room to 30hz.

Then if you plan on a sub-woofer also, try tuning to the 45hz range. This will do a few things. It will give you back some efficiency in the 45-80hz range and keep the response nearly flat to under 50hz. That gives you plenty of room to play with the xover to the sub from 60-80hz. It also puts any rise in group delay down low enough that it has little effect on the useable range.

Thanks tomcat. AE did suggest a ported box would play fairly low in 9 cu. ft. tuned to 28Hz would only go to 120 db 1M - more than enough in my room.

Love to hear from anyone that may know how the TD-15M/TPL-150H combo would compare to the GPA-604.

[DaveCan]

How about the GPA 902 driver mated to some type of waveguide instead of the Beyma? Then you would sort of have a quasi Altec M19 of sorts

[Loren42]

Looks like an interesting project.

The real story is in the polar response of the TD-15 and the Beyma TPL-150 and how well they match with each other.

2-ways with a 15" driver are very hard to get a satisfactory off-axis response throughout the full frequency range. Geddes' 2-ways are a good exception by employing a horn (waveguide) to control off-axis response and match the two drivers.

I don't know of any real data out there that will tell you if they will work and you probably will need to build a prototype and test it to see if it will work.

That's an expensive prototype, but the only way you will really know for sure unless someone has done this and will share their on and off-axis response data.

[ctrevith]

Originally Posted by DaveCan

How about the GPA 902 driver mated to some type of waveguide instead of the Beyma? Then you would sort of have a quasi Altec M19 of sorts

Thanks - interesting driver. I did a quick search on the GPA-902 and from what I've read initially it costs more and while it looks like a great driver there were no clear conclusions. Any specific info you could point to?

Originally Posted by Loren42

Looks like an interesting project.

The real story is in the polar response of the TD-15 and the Beyma TPL-150 and how well they match with each other.

2-ways with a 15" driver are very hard to get a satisfactory off-axis response throughout the full frequency range. Geddes' 2-ways are a good exception by employing a horn (waveguide) to control off-axis response and match the two drivers.

I don't know of any real data out there that will tell you if they will work and you probably will need to build a prototype and test it to see if it will work.

That's an expensive prototype, but the only way you will really know for sure unless someone has done this and will share their on and off-axis response data.

I had a pair of Heil speakers when I was in high school that really sounded great - never should have sold them. Yes, polar response is something I'm worried about. The horn that comes with the TPL-150H controls horizontal directivity to a constant 80 degrees at -6db from approx 1.2kHz through the top of its range. Vertical response is another story varying greatly over the whole range but in what looks like a consistent fashion.

Anything that can be concluded from the directivity info here?

http://profesional.beyma.com/pdf/TPL150HE.pdf

[DaveCan]

Originally Posted by ctrevith

Thanks - interesting driver. I did a quick search on the GPA-902 and from what I've read initially it costs more and while it looks like a great driver there were no clear conclusions. Any specific info you could point to?

Only that I've read that some think it is a very fine driver etc.. I had a quote a few weeks back, and for the GPA 902-8a was quoted $202 USD per driver..

Perhaps talk with John from AE and ask what he thinks mates well with his LF drivers?