Cheap TLAH drivers

[Kuro]

Hello,

I am looking at building a set of TLAHs (9 driver) and a curved SLA center (likely 6 driver).

This will be matched with a TT long with a 10" driver, built as a TV stand to hold the SLA center and PS5 and AVR.

I ran across these closeout drivers on parts-express that seem to fit the specs, and works with budget, but the fact that it has a whizzer cone has me a bit concerned.

https://www.parts-express.com/TR-48-Spe ... quantity=1

Resonant Frequency (Fs) 99.36Hz
Total Q (Qts) 1.187
Frequency Response 100 to 10,000Hz
Maximum Linear Excursion (Xmax) 1.5mm
Impedance 8Ω
Power Handling (RMS) 15 Watts /30 max.

Would the whizzer cone be an issue with the TLAH? From my understanding on line arrays, the high frequency drivers need to be as close together as possible. Would the whizzer cone effect the upper range of the woofer, and have any substantial effect in regard to comb filtering?

Or am I worrying about this too much, and the frequency range where these effects matter will have rolled off to the tweeter array?

Are there any other issues I am overlooking with this driver selection? It looks like the qts is on the high end of the accepted range, what effect would this have, if any?


Also, thanks to everyone on here. Your posts have helped me greatly in the past on my various builds. And a big thanks to Bill for creating these excellent plans! So far I have built a set of 4 driver SLAs, dual 8 TruckTuba, and an AT. All of them are amazing.

[Bill Fitzmaurice]

The whizzer won't bother anything as the crossover limits how high the drivers go. For that price I'd buy enough to do surrounds too.

[camoen74]

I had previously ordered plans for Titan and THT and have recently ordered plans for everything.

I currently have a Pioneer Elite receiver with 9.2 surround in my home theater. I have polk Center and Fronts (L&R) and Fluance Bipolars for Rear surrounds (4 total) and 2 for the front Atmos mounted toward the ceiling. I haven't decided if I will replace my subs yet...but may build THTs.

I plan to build TLAH fronts (first), then possibly Center and all Surrounds. In my search, I couldn't find much detail for the center and surrounds. I assume there is detail in the TLAH or SLA plans but will confirm when the plans arrive.

I assume that the plans i ordered are in transit. During the downtime, I was considering purchasing the TR-48 drivers because I don't want to miss that deal. At this point, I don't know how many to order so I was hoping to get a plan together based on some feedback from you all (smart individuals on this forum).

I saw a message indicating that the TLAH could be used as a center (unclear if someone mounts it verically behind the TV or horizontally in front of the TV). If there are benefits to this over the SLA center with 6 drivers, could someone post? I have a 65" LCD with a stand and planning on putting the center horizontally on the shelf below the TV. I am open to building an additional TLAH vs. the curved SLA but wanted to get pros and cons

I would like to build all of the surrounds, but until I get the plans, I don't know how many speakers to order. I saw posts about using the SLA surrounds but I don't know if there is benefit in building with more than 2 drivers (and no tweeters). Any suggestions?

Thanks in advance!

[Bill Fitzmaurice]

The TLAH may only be used as a center when placed vertically. If you must have a horizontal center it has to be an SLA CurveArray.
Snail Mail is appropriately named. I'm seeing delivery times of up to two weeks for plan USBs and CDs.
Because of the low power and limited bandwidth of surround material there's no benefit to more than two drivers or tweeters.

[camoen74]

Thanks for the quick reply!

Assuming that the center TLAH wouldn’t work well behind my TV and not wanting the TV touching the ceiling, I guess I will have to go with the horizontal SLA curved array.

Any thoughts on the TLAH fronts pairing with the Fluance (B01A5XNEPY on Amazon) surrounds…Or would you recommend that I make matching surrounds with the same speakers as the TLAH? I like my current surrounds but I don’t like that they are easily located with the bipolar tweeters. I was leaning towards building surrounds with no tweeters ( provided I don’t screw up the TLAHs).

Once I get this info, I should be able to place a speaker order. Thanks! I think these forums are awesome BTW!

[Bill Fitzmaurice]

IMO the upward firing SLA surrounds are the best surround configuration, as they're very difficult to directionally locate. You don't see commercial surrounds do it this way, because the average buyer wouldn't comprehend why they should aim up.

[Alfalfameister]

SLA comes in 4 mids 6 tweets, or 6 mids 9 tweeters configs.

I don't see (in my plans) one with only 2 drivers (or it is a matter of just building half)?

If so, 2 mids, no tweeters, and firing directly 90 degrees up? For SLA as surrounds?

[Bill Fitzmaurice]

The two driver SLA surround is at the end of the plans. It's in the sketchup as well.

[Alfalfameister]

I might have outdated plans (2014), as I didn't see it. I'll just email you privately about them. Cheers!

[Bruce Weldy]

I might have outdated plans (2014), as I didn't see it. I'll just email you privately about them. Cheers!

Not in my 2015 plans either......get you an update....

[camoen74]

I received my Goldwood 302 tweeters from PE. I found one physically damaged (cracked) as well as a few that had the leads bent - thinking they could have been returned. I tested them all with the HP filter from a bookshelf speaker. Some of them sounded ok and some of them not so much. I tested the DCR and didn't see any significant difference in Ohms tweeter to tweeter. I ran a sweep from 1800hz to 9K Hz and some of them appeared to have very different resonant freqnecies (some sounding very quiet or hollow at 1800 - 2200Hz). Realizing that the tweeters aren't broken in and filtering out the physically damaged ones, is there anything I should be doing to test them any further or match them based on perceived resonant frequencies before moving forward and installing them in my TLAHs? Looking forward to the reply.

[Bill Fitzmaurice]

Test them with pink noise, filtered at 5kHz. It's best to do so with an RTA. If you don't have any means of doing that get this app on your phone:
https://play.google.com/store/apps/deta ... ioanalyzer

Set it to Spectrum Analyzer, 1/3 octave, C Weighting, Slow Response.

[camoen74]

Thanks Bill. There are clear differences in output (some sound "thin" and the output isn't as high). I don't know if I should sort them by output and match them in the speakers based on output or if I should try to return and replace them. I don't know what my return options are for PE and if what I received in return would be any better. Any suggestions?

[Bill Fitzmaurice]

I'd do the RTA and consider any that are way off as defective. PE tends to be pretty good about returns, especially if you document the problem units with RTAs.

[camoen74]

Hi Bill (and all) - I completed the testing and have attached the histogram with results. The tweeter in the furthest bin is obviously blown. Realizing that my results are completely dependent upon my test apparatus/setup (I tried to isolate external sounds by placing the tweeters in a box with the microphone and controlling the distance to the microphone), the tweeters in bin 82.7-83.7 sound thinner and more hissy than the others. I don't know if those tweeters will significantly impact the performance of the TLAH / SLA or if I should reach out to PE in an attempt to get better quality speakers. Above 83.5, I couldn't tell the difference speaker to speaker by listening to them. Please let me know your thoughts.