John Sayers' Recording Studio Design Forum Archive

What a great forum You have here! I´ve read the threads regarding soffit mounting of speakers with growing interest. A year ago I changed my nearfields to PMC (tb2+) and the sound of these transmission line speakers still blow me (and my clients) right off the chair. The particular difference with these is that they seem to "even out" room response in a very pleasant way and sounds very natural even in average rooms. (even my friend´s untreated concrete "boom box" living room. Is it overkill to soffit mount these kind of speakers? I¨m hesitating since i think they have special designed internal filter equal to PMC:s $alot-series. Does anyone have experience of soffit mount transmission line monitors or PMC in particular?

Looking forward to hear Your opinons on this issue.

Regards

AnaMix

Anyone with expeience with transmission line speakers?
Anyone else care to comment?

Regards

AnaMix

No experience with them, although they sound like they'd be really good; I checked out a few reviews and their home page, and without having tried it I would think they'd work as well as other rear-ported speakers when soffited - but before you go to all the work of building soffits, I'd recommend a heart-to-heart talk with their design people - I guess it's possible that forcing them into 2 pi space might negatively affect their low end, but I wouldn't expect that.

Still, asking questions is almost always a good idea before committing... Steve

Got your message Anamix. The LB-1's that I have are front ported as are most of their larger cabinets. With the rear porting TB-2's, it could be an issue. Call their offices. They are very helpful for this sort of information.

What amps are you using? I have a pair of TB-2's with the Flying mole amps and enjoy them but don't think they have the low end depth of the Bryston I use on the LB-1's.

-ashley

Great advice guys, I´ll give PMC a call.

bassman:
Yes, I´ve got the moles as they were recommended by PMC. Perhaps I change to Bryston 4B but the performance/price/heat dissipation on these monoamps are just great.

best regards

AnaMix

Hi guys

Im now awaiting the swedish representative as he forward the questions to PMC. Actually he (the swede) wasn´t to excited to soffit mounting mostly due to problems with transmission line port at the rear. He also pointed out the need to modify the internal filters. What do you think, is he right?

Bassman: I read Your earlier post on pretty much the same issue, did you completed the soffit mounting of the LB-1?

-AnaMix

Hi Guys

Now I got answer from PMC, qoting

"Biggest issue with Sofit mount is 3 db lift at base frequencies.
There is a larger problem with TB2 and DB1 in Sofit as the vent is at the rear. If the vent is restricted then the units will distort.
You would need to ensure full clearance BEHIND the units for them to work . They would not be good mounted in a hole in the wall"

Comments?

Best Regards

ANAMIX

I'd still try it' the wide baffle smooths out room modes and reduces unwanted reflections. If you use John's basic plan of a vented soffit, I doubt it would cause any distortion from the rear port comment... Steve

Hi there,

Johns soffit mounts for speakers looks like a great design, however, there are no dimensions in terms of the depth from the front of the speaker to the rear of the cavity?

Can anybody please clarify the measurements from the rear of the speaker to the wall of the cavity ect ?

Allow me to wake this thread up... I have PMC TB2+S and I too was wondering about this soffit thing... I know that they are nearfield but pack such a punch that I could use them as big boys too, and am wondering if I should put them in soffit or not. I understand how to to build 'vented holes in the wall' but I am no techie or sound engineer though so what about this '3 db lift at base frequencies'? Is it something that can be sorted... or am I better off leaving those PMC's outside? Thanks!

Saying nothing about it being possible or not, but I think PMC designed their smaller speakers to be free standing nearfields. I would be cautious about moving them too far away.

Maybe it would be a good idea to contact the manufacturer, and ask them about soffit mounting their speakers? Is it advisable? Do they sell a kit for doing it? How do they suggest you roll of the bass? Etc.

- Stuart -

In the deep dark alleys which are my memory I seem to recall a thread specifically about flush mounting PMC TB2s. I think the manufacturer was contacted aswell. Like Stuart said, they could potentially be a very big help.

EDIT: http://www.johnlsayers.com/phpBB2/viewt ... &hilit=PMC

Cheers guys - Sigert I'm sure you didn't realise it but you actually linked... to this very thread I woke up with my post! I guess they were not designed for soffit so they shouldn't - I'll contact PMC anyway to ask them their thoughts about it. Thanks again!

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